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