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