Tuesday, August 31, 2021

Know when to say “NO!”

Having owned somewhere around 400 cars and mostly Honda motorcycles in the past 55 years, I seldom pass on an opportunity to pick up a vintage 1960s Honda motorcycle, especially a CB77 Super Hawk. A recent Craigslist posting was shared with me by my friend Burt, who had just seen it a few hours after it was listed.

1963 Honda 305 superhawk parts bike - $300 (Lakeside) needs restoration, mostly complete.

Burt sent my phone number to the seller who called back promptly and answered a few questions including the serial numbers which did match up to a 1963 CB77. Based upon his evaluation and answers to my questions, I packed up the Tacoma and headed out to the location, just 20 minutes away from home, hoping to find some good spares for my already running and riding 1963 CB77. I had put the bike together about 7 years ago from a pile of parts, powder-coating the whole thing black which was cheap and easy. After a 2 hour struggle, I was able to remove the pistons and complete an engine rebuild successfully. The bike was sold to a friend who sold it to her friend, then it went into storage in 2017. I bought it back, revived it, and have used it weekly as a post office box runner, but it could use a bit of bling here and there and a revised seat.

Arriving at the seller’s residence, they remarked that they owned a twin to my silver Tacoma, except theirs had 235k miles and mine 63k. The bike was sitting up on a dirt bank with 2 flat tires and both wheels locked up from rust. The drive chain was rusted solid and the front brake arms would not budge even with a plastic dead blow hammer. The tank had been left without a cap for a long time and there was no petcock. The seat pan had blue upholstery and the original outside strap buckle hardware rusted in place. The ignition switch was broken away from the key section and the left side cover knob seemed to be cemented firmly in place. The horn was missing, the speedo-tach broken and faded and even the dimmer switch functions were all frozen in place.

The bike had been painted metallic green, the rear fender replaced with a custom piece and of course, the big pull-back handlebars were all signs of a “customizing” job common in the 1960s-70s. I stared at the bike’s details for probably 15 minutes, trying to find some redeeming qualities that would make me want to drag it (literally) home, but apart from the chrome-plated factory side stand and perhaps being able to save the fuel tank, there was so much rust on every surface that it would take gallons of Metal Rescue to just get it dismantled and then refinish every surface.

I offered $200 but the seller’s wife said that her husband was “firm” on the price, so I picked up my hammer and left quietly. It’s hard to know who might pay that amount for a bike in that condition, but I guess someone will eventually haul it away. Having dismantled more than a few CB77s in that condition, I have decided that that is not the best use of my time and dollars anymore. I had to pat myself on the back for walking away from this one, as it is a rare occurrence when I do. There are times when the wise thing is to know when to say NO, and mean it.

Bill Silver

aka MrHonda 8/2021

Wednesday, August 18, 2021

Trouble-shooting the early vintage Hondas…

I am on several forums dedicated to vintage Honda motorcycles and see a lot of similar questions and complaints about various aspects of owning and reviving these 50-60-year-old machines. I thought I would go over some of the basics once again for newbies that are just getting into the hobby. So, let’s start at the beginning… You bought it and now… See * at the bottom of the story first.


It won’t start… Does it turn over and feel like there is some compression being built up in the cylinder (s)? Test compression first, even if you don’t have a gauge. Put your fingertip in the spark plug hole and turn the engine over, however you can at the same time. Holding the throttle wide open gives the best results. If you do have a gauge, it should be reading anything from 125 to 180psi. If you are looking at 75-90psi, it won’t start and run at all. Try adjusting the valves first to see if they are leaking compression past the valve heads/seats. If that doesn’t help then it is time to pull the head/engine and find out if the valves are tight/burned or the piston is scored/broken from seizures in the past.


It turns over AND has compression… Does it have spark at the spark plug? Determine if the bike requires a battery or if it has a magneto (mostly 50-80cc singles). A bike with a magneto ignition system doesn’t need a battery to make the coil spark, but if you start up a bike that has a battery in it for the lights and horn and the battery is dead, any light bulb that is normally lit will be blown out from the uncontrolled charging system output.


For bikes with battery-powered ignition systems, you MUST put in a fully-charged battery to make the engine run. If you jump-start a dead/dying battery enough to get the engine to run, the light bulbs are also at risk. Most Hondas of that era do not have voltage regulators, preferring to use the fully-charged battery as a buffer to absorb the charging system output and prevent over-voltage situations.


So… now you have compression and spark, perhaps, but does the spark come at the right time? The ignition points are basically just variable electrical switches. Setting the point gap at the highest spot on the point cam is the starting point of the ignition timing exercise. Also, the point’s contact faces must be clean and shiny to maximize the spark energy in the coil. So, set the gap at around .012-.016” and then ensure that the points are closing together and making clean contact with each other. If the point faces show a > > instead of | | contact pattern then the condensers should be replaced. Bad condensers also cause a lot of visible arcing across the point gap when the engine is running. BEWARE of any aftermarket copies of the original Nippon Denso, Hitachi, Kokusan, TEK and other OEM point sets. Many copies have incorrect dimensions for the point rubbing blocks and setting the ignition timing is nearly impossible. Daiichi, SEV, Century and other brands are not recommended. OEM points will have ND or a different symbol for Hitachi and Kokusan stamped on the point bases.


Ignition timing is set by the points just opening at the F (firing) mark. Moving the backing plate back and forth will help you to dial in the correct ignition timing. On some twins, you have to set the left side points to the normal gap, move the backing plate to where they open on the LF mark, then you will have to change the right side point gap open/close until those points open at the F mark.


Once you are sure that the ignition system is setup properly to start the engine, then you have to determine if the mechanical spark advancer is doing its advance/retard function properly. Point cams can get hung up on rust or old grease on the cam base plate shaft and that will alter how the spark timing occurs. If the point cam is slow to return to full retard at idle, then remove, mark and clean the point base shaft and the point cam, so that they both move easily back and forth. Use special point cam grease on the point cam to reduce excess rubbing and friction during operation.


So, if your compression and spark timing are all correct, then it is onto the fuel system for cleaning and testing for full function. For carburetors which have been left standing with old fuels in the float bowl for months/years, the chances of the bike starting normally are very slim. For the engine to start up the idle jet must be clear and the adjacent air bleed ports in the carburetor throat must be open.

The carburetor float chamber must have the correct level of clean, fresh fuel in order to feed the idle and power/main jet circuits. Each carburetor has a specific float level adjustment which must be adhered to for proper operation. Also, there are air bleed ports in the carburetor inlet that must be clean for proper fuel mixing. Also, be sure that the bowl vent passages in the roof of the carb body are open.

If the carburetor needs to be cleaned, use an ultrasound machine to clean out the small passages of the carburetor body and any removed OEM parts. In many cases, the aftermarket carb kits are not accurately made, so try to use as many of the original parts as possible during reassembly.

Yesterday’s carburetors are deeply affected by today’s fuels, which are generally loaded up with 10% alcohol to reduce emissions and stretch out the fuel supplies. Because the fuel is somewhat diluted, there is less energy released when the fuel vapors burn. This situation creates a lean ratio mixture condition that generally needs to be corrected with larger-sized jets, at least for the main jet circuits.

You must check all the carburetor components carefully as they can be damaged by the old fuel vapors and solids that remain inside the float bowl after months or years of neglect Most older carburetors used small brass floats which can be compromised by the acids in old fuels which etch into the metal and create pinholes. These tiny holes will allow gasoline to enter the float lobes causing them to lose buoyancy and start to sink into the float bowl. When that occurs the float cannot control the fuel level in the bowl, which creates an overflow condition.

When fuel flows out of the overflow tubes at the bottom of the bowl, you have problems with either the float valve not shutting off or the float itself. Figure out which is at fault and repair it before moving forward with the startup cycle. If you are sure that the float level is set correctly and the float valve is doing its job, then look carefully at the overflow tube in the float bowl. They have a tendency to split along the lengths of them, causing persistent fuel leaks at the tube exit.


When setting up the carburetor body, install the idle mixture screw and back it out about 1-1/2 turns to begin with. Turn the idle speed screw in until it contacts the bottom of the slide and just starts to raise it upwards. Be aware that idle screws come in two functions: Air screws and fuel screws. When you back out an air screw, more air is added to the idle mixture. When you back out the needle-like fuel screws, more gasoline is added to the mixture. For carburetors that bolt onto the back of the cylinder head, look for warped flanges and flattened out o-rings that seal the carb to the insulator, which seals to the cylinder head. Insulators will either be sealed with an o-ring or a flat gasket.

Obviously, if you are working on a twin or four-cylinder model, your work will be multiplied and you will have to make sure that the carburetors are synchronized properly on all cylinders. Twin-cylinder bikes can be synchronized by watching the slides lift off of the idle speed screws. To begin, turn the speed screws in until you see the slides just begin to lift. Then, adjust the cables at the top of the carburetor using the screw adjusters. For 350-450 CV carbs, you will have to watch both of the carburetor cable arms to ensure that they both move at the same time. REMEMBER: For twins with standard slide-type carburetors the slides are side-specific. You must see the slide bottom cutaways in the throat of the carburetor. They must always face the air filters. If you reverse the slides, you will get fouled spark plugs and a very high idle when you start the engine. Yes, they will install backward!

Fuel: When the 1960-70s bikes were built, fuel quality was much higher in octane ratings. Regular fuel was 90 something octane and premium fuel was 100-105 octane and all of it contained lead to protect the valve seats. Unless you are buying your gas at a boat marina, airport or from a race gas station, you will have to deal with the usual 10% alcohol infusion with octane ratings of 87/89/92. Gasoline chemistry has changed radically in the last century and the octane ratings used in the last century are not necessarily a match for today’s fuel ratings. My rule of thumb is to use premium fuel for vintage Hondas, either with or without alcohol. What I have discovered is that with alcohol-infused fuels, the engines run leaner and often need a 5-10% increase in the main jet sizes to compensate for the alcohol additives in today’s fuels. My recent experience is that most CB77 Super Hawks run best on a #140 main jet vs. the stock #135 main jets specified from the factory. If your machine is tuned to full normal specs and is still giving performance problems, try stepping the main jet up a size or two.

*Of course, always start the process by checking to see if the engine has enough oil to meet the marks on the dipstick. Low oil levels can often lead to seized and damaged engine parts, so making sure that the engine has sufficient oil in the engine. You might want to drain and flush the engine oil FIRST before you go forward with the above steps. If chunks of metal or a lot of aluminum specks come out of the oil, there may be expensive issues going on inside the engine that won’t be helped with the above troubleshooting and tune-up steps.

If you have followed all the above steps, you should have a running motorcycle once again.

Bill Silver 8/2021

Not so nifty, Honda CL350... at least in the beginning…

The latest “get it running” project bike came in from Colorado a few years ago and had been parked here in San Diego ever since, while the owner completed law school. It was bought without getting a second opinion but apparently did run somewhat over a year period before it was moved down to CA. It is a pseudo-cafe racer machine, based upon a 1972 CL350K4. Whoever built it up used a one-piece alloy seat with tail piece and a couple of turn signal stalks poking out of the rear on both sides, like little ant antennae. The requisite removal of the rear fender sections, stock exhaust and installation of flat bars made up the majority of the modifications at first glance.

The exhaust system had heat-wrapped, low-slung CB350 header pipes connected with some tubing adapters to connect some long chromed baloney mufflers to the chassis. The owner complained of a rather loud exhaust note, so the plan was to replace the mufflers with something hopefully quieter.

Overall, the tires were dated back into the early 2000s, the drive chain was all rusted over, the fuel tank had about a gallon of very old gasoline inside that had eaten away at the old Kreme coating that was done years before. The forks were leaking badly at the seals and the engine had a line of oil leaks around the head gasket area and just below. The battery was an off-brand that was wedged into the battery box and the original airbox with filters had been replaced by K&N type pod filters. 

The handlebars were black and flat, adorned with unknown handlebar control switches and lever brackets. All the cables were either too long or very badly cracked and the rear brake adjuster nut was riding well up the brake rod threads. It was showing about 19k miles on the speedometer, which showed signs of water leaks in and around the faces. Other than that, it was great! :>)

So, the first order of business was to remove the old battery, send the fuel tank out for cleaning and recoating, overhaul the carburetors and petcock, remove the old exhaust system and eventually address the leaking fork seals.

About $600 was spent fairly quickly on new tires, tubes, drive chain, carb kits, MOTOBATT battery, petcock repair kit, new cables, and tune-up parts. The repairs progressed as the parts arrived from near and far. The tank sealing cost $165, $70 for the battery, $80 for carb and petcock kit parts including new manifolds, new spark plugs and plug caps, and fresh 5.5mm Honda fuel line.

Starting out, the first little problem area was the fact that the carburetors were not a matched pair. 3 D on one side and 722A on the other side. The stock calibrations for the carburetors were different, so one side was running leaner than the other side. The petcock was so rusted and plugged up that a whole replacement one was installed once the tank came back from the shop. I pried out the old gas cap insert and soaked it in Metal Rescue for a day or so, then installed it back with a new cap gasket that wraps around the edges of the inner cap insert.

I blocked up the bike enough to get the forks off and discovered that the stock fork seals were too small for these forks. The fork setup appeared to be from a hydraulic brake model, eventually identified as probably a CB350 Four, which used a long damper rod screwed into the top fork nut. The fender was a match to the forks with the loop for the hydraulic hose. The standard 19” CL350 front drum brake wheel assembly bolted right into the forks, however. 3.00x19 tires seem to be difficult to source these days, so a set of IRC rubber was sourced from 4into1.com that were offered as 3.25x19” front and 3.50x18” rear. With the forks apart, the issue with seal size (not stock CL350!) became apparent. I had one leftover in stock, but had to order another one from 4into1.com as there were none in Honda dealers inventories in California.

Most of the parts came in within a week, so the front tire was changed out after the forks had been rebuilt. The battery came in and the carb overhaul was completed. With power to the system and fuel in the newly relined gas tank, I tried to fire it up to actually hear it run. And it did fire up quickly, however there was a noticeable snapping/knocking sound going on inside the engine as it idled. I tried to pinpoint the source, but it was resonating around inside the engine and not easily determined at first.

I removed the dyno cover and turned the engine over slowly by hand with a wrench on the rotor bolt. At specific times, the snap noise could be heard which gave me a clue that something was happening with the cams, timing chain or valve train components. The next challenge was to remove the top engine cover without removing the whole engine assembly. Honda didn’t leave any extra room around the top of the engine enough to remove the top head cover without either dropping the engine done off of the mounting bolts or pulling it all the way out. I had run across a similar problem with a CB350 engine where just the top rocker box cover gaskets needed to be replaced. I removed the engine mounting bolts and it left me just enough room to get the cover removed. Still that was a lot of unbolting and reassembling the engine components just to get to the top cover. I considered that there might be another option…

Using a cordless drill and some drill bits and grinding bits I ground away a little section of the frame and a matching section of the top cover mount bolt boss and eventually got enough clearance to remove the cover from the engine with everything still bolted in place. You won’t find that procedure in the shop manual, however. With the cover removed, I slowly turned the engine over again with a wrench and heard the distinctive snapping noise in and around the camshaft. As I rocked the engine back and forth very slightly, I could see the camsprocket floating back and forth on the camshaft mounting bolts!

The bolts had backed out to the point where it took more than one turn to get them tightened up against the cam sprocket again. I cleaned the bolts and secured them with Loctite and reassembled everything again. A touch of the starter button had the engine running and it was smooth and quiet like a stock engine should sound. Success for the shortcut repair!

Changing the cables lead to an interesting find. Inside the clutch lifter mechanism there was a little cutoff metal tubing spacer sitting just below the #10 ball bearing. It appeared that there was a problem with the clutch pushrod clearance and that was the answer at the moment. When I installed the new cable, I just left the steel ball in where it belonged, alone, and then discovered that someone had turned the adjustment screw all the way in the wrong direction. When the adjustment was made correctly, the cable pull feel relaxed about 30% and it now felt smooth and normal whereas it was a very hard pull when the bike arrived.

The rear fender was missing so the license plate was mounted upon an aftermarket bracket with built-in LED light that mounted onto the end of the rear axle nut! In order for it to fit, the axle nut needed to be threaded on backward in order for the cotter pin holes to line up!

I finally got it out for a test drive and the overall performance seemed to be nearly faultless. It was a little bit loud but the new mufflers have a removable baffle that can be packed for further sound-deadening purposes. Thus far, the carburetors seem to be dialed in pretty well, but a plug check will let me know more about how it is doing. I have concerns about carburetors that are just hanging on the end of a short, stubby, rubber manifold instead of being supported on both ends by an airbox and filters that are attached to the chassis.

With a new set of tires installed, the centerstand wouldn’t do its job because the aftermarket shocks were about an inch too long. The quick test rides showed no speedometer function, which first led to a discovery that the aftermarket speedometer cable wouldn’t register all the way into the front hub. Trying a spare cable, then revealed that the speedometer needle would barely move up to about 20mph and the reset trip meter knob was locked up solidly. I had a NOS speedometer for a CL450 which worked perfectly after installation. In removing the old speedometer, the single instrument light socket was rusted and the bulb was defunct. I can only imagine what the inside of the old speedometer parts look like now.

Winding down the project, the installation of a set of 12.5” rear shocks solved most of the centerstand instability. As the high spots on the tires wear down a bit it will be just fine. The bike fires up quickly and is running well now. There aren’t any apparent oil leaks, so all the gunk on the front of the cylinders and head came from leaking forks.

It isn’t real pretty, but it is all dialed in and running well now. Next!

Bill “MrHonda” Silver


Monday, July 26, 2021

Honda CL72 with tricks up its sleeve…

I actually had a quick look at this bike over a year and a half ago, when I was dropping off an auction bike for the owner. He was riding it and then it started making a noise and then BANG. I checked for compression with my finger and it didn’t seem like it had any. The exhaust valve was tight, so I loosened it and tried to start it up… BANG!

The bike owner and I live 120 miles apart, so the bike has been sitting since then waiting for one of us to connect and get/deliver the bike. After it was sent to someone nearby, the diagnosis was incomplete, so the bike finally was brought down to me for a deep dive. The bike came here as a whole machine, so we both worked together to tear off the accessory bits and lift the motor out of the chassis and onto the workbench for a look.

Once the hardware was removed and the head lifted, the horrors of the situation developed rapidly.

                                                   CL72 pistons come in many flavors...

The whole cylinder sleeve flange was broken off and lying atop the cylinder block, floating loose. The piston was all torn up with broken sections between the top ring and crown. There was shrapnel floating around inside the cylinder on top of the piston, but little damage to the combustion chamber. At first it was thought that the engine had burned a piston, but in consideration of the appearances of all of the parts, it seems like the cylinder sleeve just failed at the top and dropped down far enough to catch the top rings in the gap, which lead to catastrophic failures of the piston.

With the cylinder block removed, the cylinder walls were actually okay, apart from a groove in the damaged right side sleeve. At first, I thought that the wrist pin clip was left out or had jumped out of the pin bore, but closer inspection showed the clip still in place. Apparently, a piece of the piston debris got caught between the piston and wall causing damage. Interestingly enough the bottom of the sleeve had odd grinding marks that couldn’t be matched to anything in the region. That one is still a mystery.

Well, the pistons were the high compression versions, even though the engine was a 1965 which had lower compression pistons. The cylinders had been bored to .75 for these pistons and they didn’t show any signs of seizures or other overheating, so apparently, the cylinder wall just had a failure in the casting. I have had one other engine do that to me after a rebuild, but the cylinders had been bored to 3.00mm oversize and it failed in about 5 minutes of run time. This engine had about 1,000 miles run in on it so it was an unexpected and unforeseen failure.

Digging deeper into the cylinder head, I noticed that the spark advance shaft had more than the usual amount of free play, advancing the shaft easily with my fingertips. When the head was torn down to check for valve damage, the sprocket advance weights were missing a return spring on one side! Not sure where the spring might be, but removing the oil pump and screen didn’t bring it to the surface.

I removed the oil filter from the clutch cover housing, as it was the late-style Big Hole version, which allows some careful removal and reinstallation without pulling the whole clutch cover off. I was surprised to find a thick layer of debris inside the filter itself, but also a lack of oil present inside. Usually when the filter shaft is removed, the oil inside the housing drools out, but that wasn’t the case here. The rest of the inside of the engine appeared to be getting well lubricated, but I noticed that the engine cases and the clutch cover had been sealed with black RTV, which can be a death knell for small Honda engines when the sealant plugs off vital engine oiling channels.

So, the cylinder head came apart to check valve conditions and all had cupped seats and faces, plus one exhaust valve on the troubled right side had a nick in the edge. One other valve had the tip face getting chewed up so all four valves were replaced after I cut new seats in the head. I replaced the missing advancer weight spring and then put the puzzle pieces all back together again.

A search for a set of cylinders or a 250cc sleeve only turned up a possible new set of cylinders from David Silver Spares, described as rusty. Photos will reveal how bad it really is. Once the cylinder question is answered, then we can chase down some new pistons. I have a half dozen 250 pistons and have found that they come in three different compression heights.. 10.0:1, 9.5:1 and 8.5:1. The early ones are marked CB72 inside the skirt while the later ones have CB72 on the outside next to the pin bore.

One must choose the piston setup carefully, as Honda lowered the compression in order to reduce the number of piston seizures that occurred due to overheating. Lugging the little 250cc engine on a 300 lb motorcycle with low torque values causes the pistons to work very hard in a space of only about .001” to .002” clearances. With the known issues of erratic spark timing and today’s questionable fuel qualities that didn’t exist when the bikes were built, these engines can and will seize their little cast pistons to the cylinder walls. Usually, the seizures are momentary, but when they occur the damage has been done, leading to lowered compression readings, smoke, and oil consumption which causes oil-fouled spark plugs or sometimes even more detonation because of oil burning.

Today’s unleaded, alcohol-infused gasoline causes the engines to run lean, which adds to the heat equation, so some careful re-jetting must be considered and tested before disaster strikes. As always, the spark timing must never exceed the II hash marks on the rotor when the engine is revved beyond about 2500 rpms. Excessive spark timing leads to piston seizures even when everything else is spot-on.

Back together again…

The customer tore down a spare “rebuilt” engine from his stock and it had .50 fresh pistons installed with a little bit of water damage along one side of a cylinder but it was old rust pockets and out of the way of critical piston ring travel. After cleaning up the old gasket material, re-honing the cylinders and checking gasket surfaces for being flat, the reassembly resumed in earnest. I did replace the center guide roller with one of the reproduction items from CMSNL. Once the top end was reassembled, we lifted it back off the workbench and rolled it on a dolly back to the naked chassis. It has been very helpful to have an extra set of hands available to hoist the engines back into the frames, as loading the Scrambler engines are a bit more challenging because they load into the right side instead of a vertical lift like that of the CB and CA models.

I put a floor jack under the oil pump to help position the engine as the mounting bolts are installed. From that point, it is just nuts and bolts going back together again. After about an hour, the bike looked like its original self once more. We installed a new points plate and did a quick static timing check before starting the engine. Initially, it was acting odd, only running on nearly full choke. The old petcock and carbs had some leftover old fuel residues in the bottoms of the bowls, which may have caused some fuel feed issues. I rechecked the float levels and main jets (120s in this case) and restarted the engine. It was still coughing a bit which was caused by some late timing on the right side points. Once the timing was set to the F marks, it came fully back to life and sounded healthy. 

A brief run around the block and through the gears revealed a nice shifting transmission, even running qualities, and a front brake that needed a lot of adjusting. Beyond that, it was “mission accomplished” after some 10 hours of labor, including help from the owner. I’m still not sure what caused the liner to crack and break like that, but it may have just been a flaw in the sleeve casting. Anyway, all’s well that ends well, so another CL72 is back into circulation again.

Bill Silver aka MrHonda


Tuesday, July 20, 2021

Another vintage Honda revival.. CL175K0

When your name is out on the internet and on social media pages, you can get messages from anyone and anywhere these days. Out of nowhere, I received a message from a man in the N. San Diego County area who had owned a 1967 CL170K0 for many years, riding it for awhile, then parking it for extended periods. It was basically a “make run” request, but these can get complicated and expensive at times, especially when searching for parts on a 54 year old machine.

I was already in the area for a chiropractor appointment, so volunteered to pick it up at his residence and bring it home for a rejuvenation session. Of course, the battery was virtually dry of fluids, the tires had no measurable air pressure, but the engine still turned over. Compression checks revealed 150-170psi readings. A valve adjustment was performed, but they were only off by a thousandth of an inch or so. Hopefully, some running in time might clear off any leftover residues from a valve seat or face.

Pulling the seat and tank off revealed a very burnt looking ground wire into the harness. The owner told me that he had run the bike off a jumper when the battery was dead and the charging system took out all of the light bulbs. Headlight bulbs for these bikes are getting harder to find and very expensive in many cases. However, www.davidsilverspares.com had complete NOS units in stock for less than $85.

The whole fuel system was drained, cleaned and carbs rebuilt with new kits. One of the carburetors had a needle hold-down butterfly clip missing, so that must have been a problem for some time. I discovered that the carbs had been kitted before because the needle had a D number stamped in where the K number should be. Those parts come from the Keyster kits and are often not accurately machined.

The rear tire was a 3.50x18” trials tire, that made the bike sit on all four corners due to the circumference differences vs. the stock 3.00x18 road tire. I happened to have a new 3.00x18 rear tire in stock so it was swapped in and finally the rear tire had some space beneath it when sitting on the centerstand. The brake adjustment nut was pretty well threaded onto the brake rod, so a new set of brake shoes were installed after the brake cams were cleaned and lubricated.

The point cam on the spark advancer seemed gummy in operation, so the unit was removed and cleaned/lubed for re-installation. A fresh lead-acid battery was installed to save a few dollars on the repair bill and is plenty good enough for a bike without an electric starter system onboard.

Once the tank was drained, petcock rebuilt and new fuel lines run to the rebuilt carburetors, it was ready for a wake-up routine. I had drained the oil and serviced the oil filter spinner on the end of the crankshaft. It was refilled with 1.5 liters of 10w-30 motorcycle oil and a new set of D8HA spark plugs installed. The spark plug threads on the left side were a little bit worn, so I used a new tool that I heard about on forums which threads inside the hole and then you expand it to secure to the threads and then unscrew it to clean up the plug hole threads without having to run a tap down inside and risk leaving shavings behind.

With fresh fuel, oil, battery and spark plugs installed the bike lit off on the 2nd kick. A quick tour around the neighborhood didn’t reveal any issues. The front brake was initially grabby probably due to some rust build up inside the brake drum. Working the brake and putting on a few miles seemed to improve the situation.

The owner came back down from N. County, some 55 miles away, arriving in his VW sedan with a helmet and gear to ride it back home! I advised going that far on the freeway, but after a few surface street miles he hopped on the highway I-5 and rode some 30 miles in the right lane. I suspect the top speed for the bike is not much more than about 70-75 because the way they are geared and the lower than normal compression readings. In an hour or so, he reported back that the journey was successful and that the bike had held its own despite many miles of high rpm driving conditions.

It’s a testament of the bike’s design that it was able to sustain that kind of treatment for some 45 minutes. In the end, the bike is back on its wheels again and fully functioning once more after a 10 year snooze.

Bill Silver


1974 CB750.. from New York!

I still don’t know who exactly “referred” a Honda CB750 customer to me from the beach area, but a nice young guy contacted me to see if he could get his head gasket replaced due to a huge oil leak. Both the owner and the bike came in from New York, where the elements are not kind to motorcycles left unattended for long periods of time. This one was pretty crusty, rusty and corroded and I couldn’t help but wonder why someone would want to put more money into it, but the request was to “Fix it, please”. I told him that I wasn’t about to tear the 175 lb engine out of a CB750 anymore without help, so he said he would give a hand, wanting to know more about the process and what it needed.

The bike was sent over on a flatbed tow truck and we gingerly rolled it into the driveway for a closer look. It was covered with grease, oil, rust, corrosion and looked to have had more than a few mods. Undaunted, we did a quick scrub on the bike, hosed it off, air dried it with a compressor hose and set about dismantling the bike to extricate the greasy lump from the chassis.

After 2 hours, the engine was on a dolly and up on the workbench for disassembly and inspection. Overall, the inside of the engine looked decent, but three valves had wear-through on the stem tips, so those went on the parts list. Obviously, all the valve stem seals needed replacing, but the cam and rockers all looked reusable. Parts were ordered and I hand-cleaned the top end parts as much as I could.

New intake manifolds were ordered, but the eBay seller shipped DOHC manifolds instead of SOHC versions, which were useless, as they are much larger than the early engine parts.

Correct parts were finally shipped from my friends at 4into1.com and reassembly continued over a period of a few days, as gaskets and seals arrived.

My customer/helper went out of town for a week, so I wrangled the engine onto a bike lift and wedged it back into the frame hydraulically and with minimum amounts of exertion. All the bolts and fittings needed to be cleaned off on the wire wheel just to make them easier to install. After another 2 hours, the engine was back in the chassis and ready for cleaned-up carburetors and electrical connections.

A sad finding during installation was the fact that JB Weld epoxy was all built up around the countershaft sprocket area of the engine cases. Apparently, it threw a chain and damaged the cases, so the shop just puttied it up and sent it back out again.

The bike had an aftermarket regulator/rectifier unit spliced into the system, plus there was another mystery module mounted up near the rest of the electrical components which I left alone. The bike came with a Li-Ion battery that weighs about 6 oz but wasn’t holding a charge in the past. I hooked it up to my automotive charger on 2 amps and AGM setting and it eventually reached the desired 14-15v charge rate. The electric starter cranked the engine over with the charged battery and it did fire up after the cleaned carbs were reinstalled and a petcock screen (which was missing) placed where it belonged.

The engine fired up and sounded fairly good. The old coils had fried wire ends where they screwed into the plug caps so they were trimmed back and new caps installed to give it the best chance of running properly. So far, so good… no leaks except for the oil filter housing where someone had cut the old bolt off and notched the hole where the bolt goes through. Luckily, I had a spare CB550 filter housing handy, so that solved that problem.

The front brake needed attention, but getting the caliper off the bike was another challenge. The two big 8mm Allen bolts that hold the two caliper halves together were seized solidly. The workaround was to remove the whole front fender, then the caliper mounting bracket and then take the caliper to the workbench, forcefully loosen the two bolts, put the caliper back on the hydraulic line so I could pump the piston out and then finally it was all disassembled. The caliper piston had a ring of rust pits all the way around so new parts were ordered, along with new pads.

Once the bike was back together, I took it out for a 15 minute test run, which went okay. I put the side covers back on the frame and went for lunch. When I came back to the bike, the power to the switch was gone! Nothing there. Checked the battery, which was down to 7.7 volts, but still lit up a test light. I put the battery back on the charger and dug into the fuse box connector which looked like it had been replaced or at least some of the wires had been redone. Pulling on the red wires in the connector yielded a poorly crimped wire end and one wire pulled right out of the spade connector. I replaced the connector lugs with new ones on fresh copper and crimped it tightly together. With the rejuvenated battery, the bike came back to life with power all around.

More problems surfaces as whoever had setup the bike with low bars used a damaged turn signal switch on the left and a headlight ON-OFF switch on the right side, but there was no way to select Hi-Low beams! Not only that, but the headlight was pulsing on-off. Putting 2 and 2 together, I realized that one of the modules in the wiring side of the bike was a headlight pulsing unit, which was for safety according to the maker.

In the process of checking over the lighting components, I noticed that the tail light was not coming on nor the brake light. I checked power into the light on the harness wires and 12v was present. Removing the taillight revealed that the light socket had fractured in half, so the ground wire was connected to the back half, which was separated from the tail and brake light hot leads. Back to eBay for a $20 used tail light assembly which cured that problem.

Eventually, I felt that the bike was safe and reliable enough to give back to the customer, who rode it back home about 15 miles on the freeway reporting that it was running great! I do want to try some slightly larger main jets in the carbs, due to the pod filters and a/m 4into2 exhaust pipes, but for now, the mostly dead CB750 has been given new life for now.

  Bill Silver 7/5/21

Friday, April 30, 2021

Deja vu, all over again. A 1963 CB77 comes back home…

In my 57 years of wrangling bikes and cars, I have estimated owning about 400 vehicles during that time, but in only a few cases have I ever bought one back from the owner that I sold the car/bike to in the past.

In recent years, there was the return of a 1980 CB250RS, which I had bought new in the UK and shipped to California. I got it licensed and rode it for a few thousand miles, then sold it when I bought a new 1983 Honda 750 Interceptor. In 2014 the bike was listed locally for sale and I bought it back. A few years later, a “cafe” 1962 CB77 with Type 2 engine came back to me after the owner passed away and his wife was selling off numerous bikes, including that one. Both were eventually resold again as I continued to roll bikes in and out of my life.

Recently, I was contacted to revive (again) a 1963 CB77 that I had built from bits back in 2013. It was originally sold to a young woman who loved the look but didn’t have a great deal of motorcycle riding experience, much less keeping up on the maintenance. The bike did come back a few times for some various issues initially, then it suffered through a couple of minor crashes during its life with her. A move into a 3-story apartment with no garage necessitated the sale of the bike to a good female friend who rode scooters and various small-bore bikes. That owner rode the bike all the way to Joshua Tree Monument with a large group of women motorcyclists which covered over 300 miles of riding, mostly on highways at speed. The trip was successful, but oil leaks and other issues surfaced, so the bike was parked for a year or so. I gathered it up, brought it home, and revived it once again. The bike was treated to a set of prototype Hagon shocks that I had helped the factory develop for these bikes, so the rear suspension was much improved over the stock shocks.

Again, the bike was seldom used and then taken off the road in 2017, where it sat in a garage slowly degrading away. I had built the bike with new spokes on the powder-coated rims, but now the spokes had become rusty and beyond scrubbing up again. The tachometer cable oil leak was an ongoing issue and the battery had died over time. The fuel in the tank was left to leak out over the engine, due to a leaky petcock connection to the fuel tank. The rear tire was down to the wear bars and the bike was looking pretty sad when I gathered it up again, now 4 years later.

The fuel system was dismantled, cleaned and reassembled. I had a spare can of Caswell fuel tank sealer, so coated the tank inside to seal up an old pinhole in the saddle of the tank that I had treated with POR15 some years ago. A new AGM battery was ordered and installed. The battery that had been in the bike had about 30% left of battery fluids, so was beyond saving anyway. A spare Heidenau 3.00x18” rear tire that fit the bike was a leftover from the last CB77 recently sold, so that was spooned onto the rear rim. A little research came up with a small seal that fit inside the end of the tachometer cable and seems to have solved the persistent oil leak there. The seal cost $15, but did remedy the issue, so far.

First test rides were encouraging, as I used the bike for some local post office runs to drop off small eBay sales items. The return trips involve riding up a long uphill road which unveiled a slipping clutch issue. Right after that, the dreaded clutch pushrod seal popped out on a PO run and left a pool of oil on the ground in the parking lot and had also oiled up the entire rear end of the bike, including the new tire which was just mounted. I nursed the bike home quickly and parked it over cardboard strips to catch the oil drops and runs that were shedding off the chassis.

After removal of the right-side muffler and kickstarter cover, the errant oil seal issue was confirmed and the latest fix is to order a neat seal retainer that keeps the oil seal in the end of the transmission shaft and anchors to the countershaft sprocket bolts.

I drained the rest of the oil from the engine, then pulled the clutch cover off to check the condition of the clutch components. The 1963 bikes came with a 6 plate clutch, but I had revised it with most of a later 5 plate clutch pack, including the little retainer wires. The friction plates were still to stock thicknesses but were glazed and hardened with oil residues. The steel plates were in decent shape but were only 1.5mm whereas the later clutches have 2mm steel plates. I ordered new friction plates from an online eBay seller and found a set of 6 steel plates that were in good used condition and combined all the parts into a new clutch pack. The combination changed the stack height a little bit, but the clutch adjuster needed only a small adjustment to create the proper setup for free-play in the system. Once it was all wrapped up the clutch worked flawlessly and the transmission shifted better than most that I could recall in the past.

I worked out a deal with the ladies involved to take over custody of the bike permanently, but gave them both a key so they could come and take it for a ride if they were so inclined in the future. I went ahead and bought an aftermarket rear luggage rack from a Thai eBay seller and waited for it while I finished dialing in the bike’s carburetors and attending to a few other small oil weeps.

The luggage rack came quite quickly, but once out of the box it appeared to have been either malformed when manufactured or somehow got squeezed since then, as the whole rack was a bit twisted, the ends that go to the shocks were torqued over and the two ears that go under the seat mounts on the frame were at least 1” too tight together. I took photos of the damage and sent them back to the seller who was not wholly cooperative. First, he wanted to know if I was actually putting the rack on a CB77 and wanted photos to show that I really knew what a CB77 was and that the bike was correct for his rack. He seemed to disregard all the detailed photos I sent to show how badly out of square it was, but he continued to argue that he had never had problems with the product and that he still wasn’t sure that I was trying to put it on the correct model. Finally, I surmised that I could perhaps tweak the rack back to normal again using a bottle jack. I placed it inside the rack’s structure and wedged it apart a bit at a time until I got the width correct and was able to bolt it back into the chassis correctly. I did send him a photo of one of my books, to assure him that I really did understand what a CB77 was and that I was really trying to mount his damaged part on the correct machine.

The bike still has the original points/condenser ignition, but I had fitted it with a late Honda replacement silicon diode rectifier that had come my way, back then. So, the charging system is working fine and the new AGM battery kicks the motor over promptly every time I hit the button.

The headlight rim had a pavement mark from the earlier tipover event, so I sought to find a new or good used one. I was able to secure a new one from the UK at a cost of about $80. In the process of searching I discovered that enough parts were available to build up one of the domestic/Euro headlight assemblies which use a replaceable headlight bulb inside the reflector. A rim, reflector, parking light pigtail and socket were all acquired, along with the correct bulb base from an Ebay seller. What I lacked was a retainer wire, which is made of spring steel and formed to hold the base into the back of the reflector. The part is NLA it seems, so a piece of thick stainless steel safety wire is doing the job now. I can’t use the parking light function until I turn up a 3-position headlight switch, which is used to select just that light only.

The bike is now registered, insured and fully-functional now for its new duties as my post office runner and other short-trip bike. It still needs to have the wheels re-spoked and a few more shiny bits replaced, but it runs well, shifts effortlessly and is keeping all of its oil inside the engine cases. In the past I have had a small scooter to make the eBay post office runs, but I much prefer the little black CB77 now for that purpose. It makes my heart happy to see it waiting for me in the parking lot and often draws comments from knowledgeable bystanders. Its next big adventure will be to go on the Distinguished Gentleman’s Ride, which is the day before my birthday this year of 2021.

Bill “MrHonda” Silver 04/2021

Saturday, April 17, 2021

“Master Go” and “Grasshopper” have a CB77 adventure together

 Chapter ONE

My friend Scott called last week to say that he has heard from a guy who is new to San Diego and recently found an abandoned 1966 CB77, alongside of a neighbor’s house. The lady owner, whose husband had died over 30 years ago, gave the bike to him for nothing. Photos of a derelict looking, black, high-bar equipped Super Hawk are forwarded to me and it looks pretty grim, as it sits. Tall weeds and vines had grown through the chassis, the tires are flat, but the bike is supposed to be ALL original with only 144 miles showing on the speedometer! Yikes! Can it be true? Scott says that the new owner is excited to get the bike going again and had purchased two of my old print books, covering the Super Hawks and my Engine Repair Guide.

The new owner had contacted Scott for two reasons: One, through Linked-In, he discovered that they are both in the same high-end home theater and sound system industry and Scott's mini-bio also noted that he was a vintage motorcycle enthusiast. Having previously seen Scott’s name in the credits of one of my books, the new owner called Scott to see if he was one and the same person; audiophile and vintage bike guy, and then tells him the story of how he found the bike, while combing the neighborhood looking for his missing cat! Thanks to the cat, he finds the bike in a lady’s yard and winds up pushing it home as a project. (And yes, he also found the cat.)

Chapter TWO

During the conversation with Scott, the CB77 owner mentions that he has my books and has torn down the engine using them as a reference. He’s quoting passages of the book to Scott, as if reciting a great Shakespearian play. Scott then mentions that “MrHonda” lives 10 miles away, here in San Diego and probably could be persuaded to have a look at the motor and give some advice or assistance in the reassembly of it. The CB77 owner is EXCITED by the prospect of having the “Honda 305 guru" as an advisor for his engine repair project. Scott questions whether the bike really has 144 miles on it, as indicated on the speedometer. More photos provided of the OEM original Bridgestone tires and other details indicate original low-miles status, despite its rough-looking condition.

The neighbor lady related that she and her husband bought the bike in New York, just before moving out to California. For some reason, he was unable to register it in California and wound up just riding it around the block, every so often and just starting it up in the garage, periodically, thus the lack of driving miles. So, the “gift” bike comes without any paperwork or key, as the widow lost track of all that stuff many years ago. The story makes sense and seems plausible in light of the observed details of the bike.

Chapter THREE

I can’t remember the number of times when I have used the words, “Patience, Grasshopper, patience” with some over-eager vintage Honda fans who try to rush the process of finding parts and making repairs or completing a restoration. It has been a funny exchange between several of my “devotees” over the years as the “Master” and “Grasshopper” relationship continued in some way. Imagine being able to use that line with someone who was directly connected to the source of it. For those of you who are old enough to have watched the series, “Kung-Fu” with David Carradine, as “Kwai Chang Caine” in the 1972-75 TV series "Kung Fu." In the series, a “young Kwai Chang Caine” was played by an actor named Radames Pera. In the series, Caine's teacher, “Master Po,” called him "Grasshopper" as a child while in training at the Shaolin Temple. When young Caine was impatient or acting out, Master Po would say, “Patience, Grasshopper, Patience,” which became a famous phrase around the world.

Pera also played writer/poet John Jr. (and fiancé of Mary Ingalls) on "Little House on the Prairie" in its first three seasons and in numerous TV and movie productions from the 1970s to the mid '80s. He left Hollywood and show business after that, to start his own home audio installation business in 1988, which continues to this day.

So, what is the connection to the Honda CB77 story?

Well, Radames Pera, aka “Grasshopper” is the new owner of the CB77 project! On Valentine’s Day, we met and he brought the disassembled CB77 engine along for evaluation and eventual reassembly. He is definitely excited about learning more about the bike and engine details, so he will be watching over my shoulder while we make it go back together again, this month. We have already spoken about tempering his enthusiasm to get it finished and if he gets out of line, he has agreed that I can say “Patience, Grasshopper, patience,” if warranted. Funny, isn’t it?

Synchronicity has come into play on several levels, as my daily driver bike is a red 1989 NT650 Hawk GT, which happens to have been Radames’ first motorcycle and we both share a love for other vintage Hondas. Additionally, as I intend to wind down my motorcycle repair work further this year, I need to release extra parts in stock, so this bike is probably going to receive a lot of my spares as it comes back to life. I already have put a new battery, transmission cover, seal kit and other small parts aside for his bike and hopefully more extra parts can find new homes with this project. Radames will continue to do the chassis work on his own and after the motor comes together, the bike will rise like the Phoenix.

Chapter FOUR

Well, the engine had one stuck piston, which Radames was able to coax out of the cylinder without damaging anything. That piston had stuck piston rings in the ring lands and was of course still on STD bore. I hauled the machine shop for a wet honing and check of the bores. The “good side” was perfect, of course, but the stuck side had some staining and discoloration above the piston line, where it sat unmoved for over 35-years. Despite the look of the staining area, there was nothing that could be felt by a fingertip check, so the current plan is to reuse the cylinders, as-is and see what happens. I was able to free the stuck rings from the piston, breaking them out in small chunks. It occurred to me that I could clean the gummed-up ring lands with sparing use of a hacksaw, which worked extremely well and took only a few moments vs. spending a half-hour with a broken ring section scraping the carbon and varnish deposits from the piston grooves.

In cleaning the engine cases I was quite disturbed to find that the same “mistake” made by numerous unqualified mechanics during assembly was in fact performed at the factory! That pesky little crankshaft locating pin, which locates the roller main bearing, was indeed pushed into the cases by Honda assemblers! I had to do the same repairs on this factory-assembled engine that I have done to about 3 previous engines in the past year or so. What’s SO HARD about paying attention to the main bearing location when putting the cases together? Apparently, it is more of a challenge than I thought. I guess I will just keep fixing them, when I find them, as long as I continue repair work this year.

Radames had cleaned most of the engine parts, all of which arrived in a couple of boxes with well-marked Zip-Lock baggies. I figured that this was going to be my only chance to be able to see a near-new 305 engine as it came from the factory, all apart.

As mentioned, I discovered the misaligned bearing/pin issue which needed attention, first thing. Once that repair was completed, I could turn my attention to setting up the top case with a properly installed crankshaft and transmission gearsets. Radames wanted to watch as the reassembly process unfolded, so I waited until his arrival, then went to work describing the process and then taking him through the steps of “X-ing” the gearbox to move the gear spacing closer together for the 1-2 and 2-3 shift steps. Remember that this is an engine with 144 original miles on it, so any wear should be at an absolute minimum. That said, the gear dog overlap on one set of gears was probably about 30%; a likely candidate for premature “2nd gear jumping” conditions as the miles accumulated. I installed a pair of the .040” offset cotters, which increased engagement depth to about 60%, from my dwindling stock of these much-needed pieces. After changing the transmission shaft seals, including the pushrod seal, I inspected the end of the pushrod, which is generally dished out on the end where the ball bearing rides up against the shaft end surface. This one barely had a mark on it.

With the crankshaft sitting properly on its locating pins and the transmission mods completed, it was time to button up the crankcase halves. I have some 3-Bond equivalent sealer from the local auto parts store and painted up the bottom case half, then dropped it over the top, taking time to check all the affected seals so that they hadn’t moved out of their designated locations, flush with the engine case surfaces. I replaced the soft, aluminum sealing washer for the special 6mm nut on the bottom case, otherwise reusing all the original fasteners which had been recently removed. Radames was a great assistant, cleaning peripheral engine castings and nuts/bolts/washers on the nearby bench grinder’s soft wire brush wheel. This is one of the few times in my life where I had some company during an engine build and it made the time go by quickly, although it was slowed a little when I took some time to explain an assembly step. Radames is a very congenial and polite guy and as we had this chance to share stories, it was plain that he was a real “Honda guy” (as in, you meet the nicest people on a Honda).

In the midst of cleaning the oil pump screen, he accidentally caught the brass screen mesh with the spinning wire wheel, shredding it in a couple of spots. He came to me, sheepishly, to ask if it could be fixed or okay to use with the damage recently inflicted. I assured him that it was NOT okay to use and that it couldn’t be easily fixed, so we put in a call to Scott Sylvester, who graciously provided a near-new part at no cost. We all mused about what other purpose you could find for damaged oil pump screen; perhaps an ashtray or pen holder for the desk…

Once the cases were assembled, we were ready to install pistons and cylinders next. Radames had brought the two STD bore pistons to me and one had very stuck rings in the top two ring lands. He had soaked the pistons in solvent for a couple of days, but there was no apparent change in their condition. Before he arrived the following day, I took the piston and worked a small-tipped scribe into the tiny end gap of the rings, then tapped on the tool with a small tack hammer, angling the tool towards one open end of the ring. After a few hard raps, the end of the ring began to move back and slightly outwards. I squirted in some penetrating oil and kept tapping on the ring end, until it moved out enough to grab with a pair of duckbill pliers. The ring snapped off about 1” in, but gave me more of a cross-section to use as leverage to keep the process going. Little-by-little, the rings came off in small chunks until I had the piston clear of ring debris. As previously described, I used a hacksaw to clear the varnish/rust/corrosion in the ring lands and dressed up a few nicks on the piston itself. Radames had procured some STD piston rings from an aftermarket source, which appeared to be made of steel, instead of cast iron, including a nice 3-piece oil ring set. The rings easily installed on the pistons and we proceeded to lube up the wrist pins and marry the parts together again. Another indicator of the original mileage of the engine was that the wrist pin bores on the rods were absolutely flawless inside. There was none of the usual scoring and wear marks, which is normally seen on high-mileage motors. This engine was definitely as advertised; a 144-mile original.

With freshly honed cylinders, we lightly lubed up the parts and coaxed the cylinders down over the pistons/rings. When the cylinders are at STD bore, the bottom chamfers of the liners have a full width on the beveled edge to help guide the rings into the piston ring lands with greater ease. With pistons and cylinders all installed, we pulled the head out of the box for inspection. There was just a bit of some water/rust spots on the backside of the left intake valve stem and valve head, so I decided that we better remove all the valves and clean the heads, stems and ports of any corrosion or debris. It was great to have an extra set of hands holding the valve spring compressor and/or head while I fished out the keepers and later re-installed them on the newly-cleaned valves. There was just a little bit of some scoring on a few locations of the cam lobes, otherwise the top end parts looked like new inside. Once we finished the valve cleanup I reinstalled the rocker arms and pins, then dropped the whole assembly over the waiting cylinder studs and head gasket. We verified the camshaft timing with crankshaft and camshaft marks, reusing the camchain with a new master link clip from my spares stock.

Radames cleaned up the top cylinder head cover with the wire-wheel brushes and I buttoned down the top end to 15 ft. lbs. on all eight stud nuts. This was a motor where Honda began to use copper washers on the outer studs and flat steel washers on the inner four locations. The camchain guide wheel was replaced, mostly due to some hardness and a series of camchain marks left in the surface from sitting for over 30 years in the same spot. The camchain tensioner wheel seemed to be pliable and was reused without concern.

On to the clutch side, where I had already installed the clutch outer and primary chain/sprocket set on the shafts. Even though he had been reading an older version of my Rebuild Manual, which mistakenly advised to discard them, Radames had removed the clutch plate retainer wires carefully and hung on to them "for some strange reason, mostly because they were so pristine and he figured they were part of the original engineering." Surprisingly, there were no signs of the dreaded “stuck clutch” syndrome, although there were a few impressions of the friction plates left behind, mostly as stain marks. I checked all the parts over and then just reassembled it as it was. The primary chain still had minimal chain stretch and everything continued to look “fresh” inside. We cleaned the oil filter body and cap, installed a new o-ring between the two and set the assembly up on the motor with the drive chain installed and the thrust washer located next to the index pin on the filter shaft.

The motor build is winding down, with just the oil pump to install and carbs to rebuild. Even though the outside engine castings are still scaly, dark and have corrosion in the nooks and crannies, this motor should be a quiet and easy runner well into the distant future.

I am enjoying my new friendship with “Grasshopper” who now calls me “Master Go” (a take-off on “Master Po”) for my ability to reanimate and revive dead and dying vintage Hondas and make them GO once again. This has been a refreshingly fun CB77 project.

Bill “MrHonda” Silver

aka “Master Go”

Tuesday, March 30, 2021

Learning to speak Italian… again!

 I really have to stop throwing out internet bids on “interesting” bikes and forgetting that I did it until I receive notice that I have “won the auction”.

Those of you who have followed my ramblings over the past 10 years (or more) might recall that I acquired a somewhat troublesome Benelli Sei (750 six-cylinder) machine from a local seller who had had it since the 1970s. That bike was fun to ride and sounded amazing… when it would start. Even a $500 ignition system never insured that the engine would fire up easily. That, along with the factory defective transmission gearset (there was a recall that the bike never received) led me to let it go to a local Italian bike dealer who had the bike restored.

So, here we are again, with almost the same bike, but with fewer cylinders this time. The Benelli Quattro 500 is the Honda CB500 engine clone in virtually the same chassis as the Sei. The big departure is that instead of a double-disc Brembo front brake, it has a double-sided drum brake system with 4 brake shoes upfront.

The bike caught my eye on some Internet link to a big auction in Wisconsin in mid-Oct. It was open to internet bids a few weeks ahead of the actual date, so I thought I would test the waters to see how much interest there was in this rare machine. Benelli updated the models with the double-disc brake wheel later on, but few of these bikes were probably ever sold in the US in either form. I do recall seeing one for sale locally a number of years ago and visiting the seller’s place to see it in the flesh/metal. It, too, was a drum-brake model, but it wasn’t running and I shied away from it due to lack of parts and general knowledge of the series.

By the time I paid for this bike, plus a hefty 18% buyers fee and rounded up a U-ship guy to haul it out for $450, the initial bid cost had increased by 50% again. All that was shown in the auction page was both sides of the green bike and a short sentence about the frame number and perhaps the mileage on the odometer. The auction company did provide a WI title a few weeks after the bike arrived, which is helpful for getting a CA title for the bike, but you still have to jump through the DMV/CHP hoops to finalize the paperwork.

The main source for replacement parts is a company in Germany, which seemed to have gathered up all the remaining Benelli parts for all the models they could find. They have microfiche illustrations on-line and generally ship parts out quickly and at reasonable prices, all things considered. I did inquire about the H-shaped molded fuel hose connector in advance of receiving the bike and they did not have a replacement part for that item. There are four carburetors and two petcocks to connect all the plumbing together so I will have to round up T-fittings to get it all fueling properly.


The bike arrived within 10 days from the auction, riding tail-gunner on the back of a long, double-axle open trailer. At 20 feet, it doesn’t look TOO bad, but as you got closer the condition issues became more and more apparent. Fortunately, it did have some air in the tires and the 4 shoe front brake did function to a point. The friendly driver helped me push it up the driveway and into the awaiting bike lift for future repairs and a deeper inspection of all systems. It was one of those heart-stopping moments where you say to yourself, “What did I get myself into now?”

The first look revealed that there were NO spark plugs in the engine, no ignition switch key provided and the engine was LOCKED UP solid. The first thing to do was to squirt WD40 penetrating oil down each spark plug hole and hope that it would work some magic on the stuck pistons.

The design of the battery box is such that you cannot remove the backside of the air filter box to service the filter. Removal of various attached electrical components finally allowed the battery box removal. At that point, the bolt holding the filter cover turned out to be part of the inside of the housing, not accessible unless you remove the carburetors and airbox. The carburetors are connected with intake manifold rubbers which attach to intake manifolds which are bolted onto the backside of the cylinder head. The air filter box connects to the carburetors with short connectors, which unlike the outside angled versions on a CB500 Honda, are all straight-back designed parts. Pulling the connectors off the airbox and back off the carburetors allowed for carburetor removal. One of the carburetor tops was missing and the throttle cable had already been disconnected. SOMEONE had been in there before, probably trying to get it running sometime in the past 10-20 years.

On the plus side, the odometer only showed 1506 miles and the original Pirelli branded tires were showing little wear, which seemed to verify the miles shown on the speedometer. There was rust everywhere on chromed parts, other than the fenders, which were unaffected for some reason. There was surface rust inside the fuel tank, of course, but the carburetors were clean inside the bowls. The plastic meter box, which mounts to the upper fork bridge with a couple of bolts was broken at both attachment points. It was déjà vu all over again, as the basic architecture of the Quattro 500 is nearly identical to the 6-cylinder Sei. The Sei had double disc brakes up front, but both bikes shared the same rear hub and suspension. The Sei has alloy rims, where the cheaper 500 was left with chrome steel hoops, which were both rusted badly on this machine.

The fork ears had been chromed, along with the front brake hub stays from the factory. The brake stays were suffering from peeling chrome and the fork ears were in similar condition. The chromed headlight bucket was somewhat better, but the headlight rim chrome was badly pitted. The 4into 4 mufflers were solid, but with surface rust and pitting down in the creases. The header pipes were still in remarkably good condition, however.

Once the carburetors were removed, work commenced on getting the top end of the engine removed for damage assessment. Unlike Honda, Benelli engineers used #1 Phillips head screws to retain the top rocker arm cover. Fortunately, they mostly loosened with a few blows of the impact driver with a matching driver tip. More challenges were revealed when two of the Allen screws that hold the top cover end caps wouldn’t come out, stripping the hex heads of the 5mm screws. After trying various methods of removal, the heads were drilled off so the caps could be taken off. The end caps cover the last two end screws that hold the top cover to the cylinder head. The screws thread into the ends of the rocker arm shafts and there was no apparent reason for two to come off and two to be firmly entrenched in their positions. It took about a half-hour of careful drilling the screws out of the ends of the shafts, then rethreading the holes successfully. The cover then came off easily revealing shiny metal parts inside. The rocker arm pads were all like new and the camshaft lobes appeared to be barely broken in.

The camshaft is secured to the camsprocket with two bolts, but somehow the engine had stopped with both bolts lying right at horizontal positions. It’s tight quarters in there, so although the camshaft bolts could be accessed (remember the engine was frozen), you can’t back them all the way out of the camshaft sprocket as the heads hit the inside of the cylinder head opening. I tried to loosen the camsprocket bolts with an open-ended wrench, but they didn’t budge at all. I figured that the bolts had been installed with Lock-tite thread locker, so the only option was to try to loosen them with a large sharp chisel. The chisel was able to catch a corner of the bolts at just the right angle, but it took considerable amount of hammering to get them to begin to rotate loose from the camshaft bolt holes.

Eventually, both bolts were loosened successfully, but couldn’t be removed due to their proximity to the edges of the cylinder head. A Dremel tool with a cut-off wheel was used to cut half of the bolt head away just enough to allow the bolt to be removed from the forward bolt hole. The rear one remained in place, however. Using a long-handled adjustable wrench, I applied some torque on the crankshaft bolt, hoping that the engine would give just a little bit. Suddenly, the crankshaft turned about 10 degrees and the camshaft bolt was then clear of the cylinder head for removal. With the camchain free of the camshaft, the engine was turned back and forth a few times, finally allowing for full rotation of the crankshaft and full movement of the pistons.

The camchain tensioner bolts to the back of the head and cylinder with 2 bolts, but unlike Honda’s design, the mechanism can’t be locked in place for removal. When the bolts were removed, the tensioner spring wanted to push up against the back of the camchain, preventing removal of the camchain from the sprocket teeth. The tensioner was pulled upwards, but hit the frame backbone tube before it was clear of the cylinder head. Finally, it appeared that the tensioner could be compressed with my fingers and the whole unit rotated 90 degrees, which then allowed the top to be tipped over and just clear of the frame tube.

Once the camchain was off the camsprocket, the camshaft was removed and a wire attached to the camchain to prevent it from dropping too far into the engine. The cylinder head is attached with a series of flanged nuts and washers, some of which are sealed off by little rubber plugs in the head. With all the nuts removed, the head pulled up with a little nudging here and there. The valves had quite a bit of soft carbon on them, but showed little signs of use. The now-exposed piston crowns showed some signs of varnish, carbon and moisture corrosion. The cylinder bores had some pitting around the edges of where the pistons were sitting for so many years. The corrosion had eaten into the bores just enough to catch a fingernail on the edges, so the choice was to pull the cylinders for a re-bore.

A set of .50 aftermarket Honda CB500 pistons/rings were ordered up from Japan for $125 and the cylinders will go off to my favorite machine shop for $160 of machine work. Lots of scraping was involved to get the leftover gasket material off the engine cases, all the while trying to keep the loose bits from entering the open bores in the crankcase. The pistons all came off of the pins with little fuss, so there is no concern about damaged pin bores in the rods.

Progressing slowly…

The a/m pistons came in from Japan in about a week. My machinist bored the cylinders and noted that one piston was a bit smaller than the other three, so bored the holes accordingly. After some wire-brushing to clean off excess corrosion, the cylinders got a bit of color added back. Benelli actually painted the cylinder blocks gold and the heads black from the factory! After an hour of careful prepping and assembly, the cylinders glided onto the pistons and the assembly awaited the completion of the cylinder head.

The cylinder head was disassembled and de-carboned. All the valve faces and seats looked great, but valve stem seals were hardened, so were replaced with gasket kit parts. In the process of reassembly one of the valve stem keepers dematerialized and could not be recovered despite an extensive search of the immediate area. I discovered that the valves were 5.5mm stems like the Honda valve stem sizes, but Honda keepers didn’t fit, so replacements have to come from Germany.

I was ordering parts from Benelli-Bauer anyway, as they are one of the last couple of resources for NOS Benelli parts. They can supply replacement instrument cases and most everything else that I have asked for so far.

In the meantime, I decided to go the poor man's route and have the rims powder-coated satin black, along with the formerly-chromed fork ears. Some new tires were ordered and after all the spokes were cleaned up, the finished rims were re-spoked back to the de-rusted hubs. There was extensive amounts of rust inside the drums, however, it did clean off with extensive use of wire wheels and abrasives. The brake shoes were glazed and had a thin film of corrosion embedded into the faces. A little light sanding brought back the original surfaces.

Rather than purchase all the Benelli gasket parts, one-by-one, I just ordered up a whole CB500 Four gasket kit and installed all of those parts without issue. Apart from the slightly-angled forward cylinders, much of the top end components are exact dimensions of Honda’s OEM CB500 designs.

The parts order from Germany took almost 2 weeks to arrive, so to speed up the assembly process an OEM Honda exhaust valve was ordered to match the keepers that were already purchased, but didn’t fit the groove pattern on the Benelli valve stem. Problem solved and the cylinder head was bolted down, torqued to specs. Two new camsprocket bolts were ordered to replace the butchered ones and the rest of the original parts reinstalled.

My experience with the Benelli Sei mirrored the current one of the Quattro. The intake manifold rubbers were broken/cracked causing obvious air leaks. On the Sei, I ordered up OEM Honda manifolds and installed a set on the Sei, which did not have the original airbox in place. The manifolds were a little longer than the originals, but it didn’t matter because of the pod filter installation. The Quattro carb/manifold/airbox combo is a REALLY tight fit; even worse than a standard CB500-550 setup.

Sadly, after the long wait for the box of parts from Germany, it became obvious that the intake manifolds shipped were of two types/lengths. Three might have been actual Sei units and one an actual Quattro replacement part. A message back to Germany, accompanied with photos, confirmed the mistake and a promise to ship the correct parts came back quickly.

Eyeballing the manifold situation, it seemed that the “wrong ones” could be used in the interim but because they were of a thicker material the original manifold clamps wouldn’t reach around to fit the increased diameter. Also, the process of wedging the carburetor rack in between the bolt-on manifold stubs on the head it became apparent that there was left no room for the carburetor rack to fit between the two components. I would imagine that the “correct” way to remove/replace the carburetors is to loosen the engine mounts and tilt it forward, which is required on a CBX Honda Six.

To override that necessity, I removed the manifold stub bolts and replaced them with bolts, so I could slide the whole assembly in laterally and fit the carb inlets to the new air cleaner box connectors. I could only use 2 of the original rubber manifold clamps on the one correct manifold that was supplied, so the other three were clamped with 2” hose clamps that I had on hand. The two rubber manifold types have different ribbed patterns, but they were close enough to allow a tight fit once paired with new clamps.

Another couple of hours were spent doing R&R on the meter box installation, which was a snug fit for all the components. All the wiring connections to the instrument warning lights needed to be disconnected so the harness could be pulled through the small slit on the bottom of the meter box housing. The wiring diagrams found online were all in German or Italian and of very faint and small drawings. That had to be reworked on the computer and printed out to help with the wiring installation. The recommended replacement Yuasa battery had side posts instead of top posts, so some angled adapters were fabricated. Fortunately, apart from some blown-out bulbs and some that had melted the plastic upper meter housing plate, the electrics mostly came to life without blowing any fuses. The fuse block is typically mid-20th Century design with little bullet-ended ceramic fuses and flimsy fuse holder tabs. Corrosion had built up on the ends, so everything needed cleaning to promote good electrical connectivity.

The ignition points were corroded, so required more cleaning and adjustment. I hesitantly tried the starter button and the engine began to spin over, somewhat slowly, but the result was encouraging.

The fuel tank was cleaned and sealed with 2 part Caswell epoxy coatings. New generic Italian-style petcocks were located and installed to complete the fuel tank repairs. Some ¼” T fittings were purchased at the auto parts store and little pieces of 5.5 OEM Honda fuel line were cut up and fitted to tie the fuel system components together.

Initially, the engine spun over, but wouldn’t fire up, even with the choke fully applied. There is a lot of friction with new pistons/rings and a lack of ring sealing in the beginning which caused some difficulties in getting the engine spun over fast enough to get everything synced up, but with a jumper system in place, the long-dormant engine finally fired up on all cylinders, sounding quite like a copy of a Honda CB500 Four with 4 into 4 exhaust pipes. The carbs were fussy, at first. The idle speed was erratic, either too low or too high, probably owing to a sticking spark advancer unit.

The engine does start and run, but not idle well. The charging system light stayed ON, so the left generator cover was removed for inspection. The Bosch charging system uses a set of brushes to contact the slip rings on the end of the rotor shaft, not unlike an automotive alternator. While the components all appeared to be in good condition and electrical wiring checked okay, the whole outer brush/stator assembly was basically just floating on the end of the rotor shaft because the four 5mm mounting bolts were MISSING! Long 5x45mm bolts are not easily found locally, so a quick look online gave some clues about where to find them. I called local hardware/bolt stores and discovered that there were some in stock… 45 of them in a box! I only needed 3, but the whole box was only $6 and change, so I bought the box and have more than 40 to share with anyone out there who might need such a fastener.

The bike continued to be hard starting, didn’t want to idle and one carburetor began to overflow due to a failed plastic float assembly. Carb kits were ordered and the wait continues for replacement intake manifold rubber connectors. All the spares will go with the bike, which has been put up for sale now.

As has happened several times in the past, I am facing surgery again, this time for a worn-out ankle. The recovery requires 3 months of non-weight bearing on the right foot, so getting this project wrapped up and ready for sale has become a race against time.

A quick trip to the CHP office for verification and then back to DMV to push through the completed paperwork was successful, so the bike can be officially titled in the state of California. Having a titled bike helps the sales process immensely so I always do the legwork to get the paperwork in order for the next owner.

I have to promise myself NOT to repeat this process again, especially with another rare Italian Honda copy model, such as the Quattro 500. In an eerie coincidence, during the Quattro project, I was contacted by a man who I met at the January 2018 Mods and Rockers ride event. He had bought a storage unit full of bikes, including a silver 1976 Benelli Sei! He wasn’t going to sell it right away (although there is always a price that works in the end), but needed someone’s help to get his running properly. I offered to help, but warned him of my upcoming surgery and lack of ability to do motorcycle work for at least three months afterwards. Unfortunately, the sands of time have about run out on that offer…

Bill Silver aka “MrItalianHonda” for the end of 2018.