Wednesday, May 24, 2023

Lucky... for 75 years.

 75 Years of being lucky…

It sounds like a very large number when you say it out loud… 75! Really? 27,375 days, starting in the year that Soichiro Honda organized Honda Motor Corp. Somehow, that connection lead me to become known as MrHonda to a worldwide community of enthusiasts. At least, that is how it seems. Counting your blessings, in a life lived this long, would take another year, I guess. But, here are some highlights that come to mind this day...

Lucky, to have been born and raised in America’s Finest City. A place of nearly year-round motorcycle riding weather, where tornados, hurricanes, and sub-zero temperatures do not exist.

Lucky, to have been raised by loving parents and sharing a life with my sister, Carole, and brother Jim.

Lucky, to have had some “mechanical genes” that lead me to 3 years of auto-shop in high school and eventually learning something valuable from over 400 cars and motorcycles (mostly Hondas) that I could share with so many others.

Lucky, to have avoided the Vietnam War experience, when I was guided to join the USAF and wound up learning about electronics and winding up in Puerto Rico for my overseas assignment with the Hurricane Hunters. I had signed up to be an aircraft mechanic, only to find out that they were all going to be sent to Vietnam. Divine intervention opened up a new opportunity for training and a whole different life experience, free of death, destruction, and war trauma.

Lucky, to have inherited the “writer gene” from my Grandmother, which spurred me on to learn to type and create books, blogs, and emails: and even take over the VJMC newsletter for a few years.

Lucky, to have my daughter Sara, who with her loving husband Alex, has been raising energetic and creative children who will take my DNA into the future.

Lucky, to have survived three major motorcycle accidents, suffering road rash and some broken bones, rather than paralysis or death. Ironically, my father crashed small private planes three times and survived.

Lucky, to have the presence of my 95-year-old mother, Shirley, who still drives, cooks, knits, and laughs at my humor over the dinner table.

Lucky, to be able to keep working on vintage Honda bikes which the local populace keeps dragging up the driveway for rehabilitation.

Lucky, to have the VA health system to care for my aging bones and keep me healthy and well.

Lucky, to be able to ride out on my 1991 Honda Hawk GT650 with my Jamuligan friends every Sunday for breakfast rides and discussions about bikes and life in general.

Lucky, to have experienced two marriages and the adventures that came with those relationships.

Lucky, to have so many friends, near and far, who feel comfortable asking for help or giving it to me in times of need.

Lucky, to have technology to be able to share this story with a whole LOT of people all at once.

Lucky, to have followed my instincts and interest in holistic healing to learn of the EFT tapping method of healing PTSD and neutralizing unhelpful memories. To share this kind of transformation work with others fills me with joy with each client experience.

I have a little framed poem that I wrote for my dear step-father, Ray Yahnke, who nurtured our family for over 50 years. It hangs on my bedroom wall. It was called “Three-quarter Years,” and was written in 1997. I read it and think that it was a pretty good poem for him and for the times we shared. 

And now, here I am at the three-quarter years mark, filled with gratitude for the life lived in safety, love, and support from family, friends and enthusiastic Honda owners all over the world.

Thanks to all who have shared the journey with me.

Bill Silver

aka MrHonda

Wednesday, May 10, 2023

CSI-Spring Valley, SL350 mystery…

The SL350 Honda series of MotoSport models had a short-lived and interesting life span. Honda spawned the SL series models in 1969, starting with the one-year-only SL90, adding SL70, SL125, and SL175 and finishing with the 350 twins. Honda’s CL350s were hardly off-road worthy, being based upon the heavy CB350 street models, by adding some handlebars, cosmetics and high mounted muffler system. The initial SL350 was a meager attempt to make the bike more off-road friendly, at least a little bit, but they continued to make the bike with an electric starter which added a good ten pounds to the bike when you consider the starter motor/starter clutch parts, the starter solenoid, wiring, and a heavier battery.

The SL350K0 continued to use the basic CB/CL engine with large CV carburetors, but the power delivery might have been altered a bit by the low-slung black mufflers, mounted on both sides of the bike.

Honda got a lot more serious with the SL350K1, when they totally revamped the bike, adding alloy fenders, deleting the electric starter system, then installing low-end power-producing modifications such as a small-port cylinder head, revised camshaft, and a set of 24mm slide-type carburetors. These revisions helped to build mid-range power at the expense of cutting off the 10k rpm power peak that the earlier engines were producing. Not content with the K1 mods, Honda added 35mm fork tubes to the front end, replacing the 33mm units that were commonly used during this period.

The SL350K2 in this case, came from a BAT ( auction, which made its way all the way from FLA to SoCal. The local owner bought it somewhat on a whim, at what seemed to be a decent price for what appeared to be a restored machine. Certainly the paint and bodywork were all up to a good standard, but there were some noted “oil leaks” and running problems that were addressed by adding a set of Chinese-made carburetors and manifold adapters, plus some large pod-type filters.

Once it arrived, the bike was taken out for a test run and it promptly died about 10 miles out from the garage. After popping the gas cap open to check fuel level and perhaps lessen any effects of a restricted fuel cap vent, the bike fired back up and was driven back home safely. In an odd quirk of fate, the owner had the bike out in his front yard when another friend/customer whose CL77 I had revived after a 10-year sleep happened to drive by the house and spotted the bike. He stopped to talk to the owner and the discussion arose about the bike’s running issues. My name was given as a possible resource and I got the call the next day.

The bike and owner live about 35 miles away, near my sister’s house and my chiropractor's office, which I visit once a month. Being in the area, I swung by to have a look/listen to the bike. The bike was started up after a few kicks and initially sounded quite noisy in the top end, plus there were oil traces at various points on the back of the engine cases and around both sides of the cylinder head. After a discussion of the possibilities, I loaded it up and brought it home for some TLC and hopefully resolution to the various issues.

The first actions were to remove the beautifully painted (and signed) fuel tank and lean the bike over to the right side against the wall to keep from losing oil from the dyno cover when it was removed. Rocking the crankshaft back and forth with a 14mm wrench, it was obvious that the camchain needed to be adjusted. The locking bolt was loosened and the little snapping sound of the plunger jumping forward was heard. Rechecking the crankshaft motion again and now the camshaft was following the crankshaft motion precisely. Next step was to check the valve clearances, all of which were somewhat loose beyond specifications. With the dyno cover off, the point cover was removed and the points checked for proper timing, but only after the plate and advancer were removed to reveal a leaking camshaft oil seal. I happened to have one in stock, so it was replaced and everything reassembled and adjusted.

The fuel tank was replaced and the bike fired up with the little black carburetor chokes engaged. The engine was much quieter now and a quick test ride revealed decent power, but the bike stalled out at a stop sign, then restarted again with a few kicks. For some reason, the kickstarter mechanism seems very difficult to engage the engine at an angle that promotes easy starting. Plus the right side muffler is close to the kickstarter arm path, when pushed down with your leg.

Knowing that the valves were set correctly and the ignition timing was set to specs, the gas cap was checked by prying out the cap innards and drilling it apart. There are several discs of metal that comprise the cap vent system, but despite years of corrosion, the vent holes appeared to be open sufficiently to allow proper tank venting. When the vent system is blocked, the fuel flow is restricted or stops due to a vacuum being produced inside the tank. I cleaned the parts and used a pop rivet to reassemble the various bits, including replacing the outer cap seal.

The bike was driven again, with mostly the same results. Ran fine under power, but sitting still at idle, would tend to just die out after a minute. The bike came with a stock set of 24mm carbs, which had been “rebuilt” but was suffering from a left-side persistent leak. When the carbs were inspected, the float valve needle was found to be upside down, causing a fuel leak problem. After turning the needle around and resetting the float levels, the Chinese set was removed and the OEM carbs were installed. I had to make some new gaskets for the manifold from cork material, but the carbs held fuel just fine and the bike started up somewhat easier. But, again, the test ride was fine, but the bike stalled in the driveway.

The spark plugs were removed and found to be somewhat fuel-fouled, possibly due to the Keyster carb kit parts installed. Compression readings were about 145 psi, which is on the low end of Honda’s specifications. There was more than a little blow-by coming out of the breather hose, which dripped some oil solids down on the swing arm where the tube terminated. I figured that the engine, which turned out to be from a K1, and bored. .50 oversize hadn’t had enough running time to seat in the new rings, assuming that it was machined and assembled correctly.

Oil was dripping into the right side cylinder head cover/cam bearing housing from a leaking tach drive seal and might have been leaking past the o-rings that seal the valve adjuster shafts. With some careful work, you can remove the cam bearings, one at a time, and inspect the bearings, gasket, and o-rings. One of the o-rings had a bit of an odd kink to it, but nothing looked out of the ordinary. The tach seal was replaced and the right side cover was installed. I had already replaced the left side cam seal but pulled the bearing back anyway to check the o-rings, which were kind of stiff. I found some thinner o-rings that were the same OD and added them to the cover shafts. The other source of oil leaks seemed to be in the top camshaft cover for the engine and possibly the left side of the head gasket.

Checking the ignition system included running tests on the aftermarket coils that were installed. Ohm tests showed about 3 ohm primary resistance vs. 4.5 for factory coils and both showed about 10k ohm readings on the secondary side. But when the bike was running, a dynamic test light was hooked up revealing that the right side was firing steadily, but the left side was firing erratically, I had already made a small adjustment to the point fixed contact which was showing contact at the edge of the set instead of more towards the center. Cleaned and re-gapped again, timed accurately, the left side continued to spark erratically which drags down the right side cylinder function. This can alter the vacuum signals to the carburetor mixture circuits, perhaps resulting in fuel fouling. I had already lowered the slide needles to the leanest position, but the idle jets may be out of spec. Idle mixture screws were not terribly responsive at idle. 

So, at the moment, the combination of erratic ignition firing and possible idle jet calibrations was the probable cause of the stalling problems. A new set of 4.5-ohm coils were ordered, but in checking the charging system the rectifier wires, which were wrapped with electrical tape, appeared to have a loose positive battery output connection that had been “repaired” with a small bent piece of wire hooked up to what remained of the original electrical connection on the rectifier. Another rectifier was ordered, but digging through my spares, I discovered a replacement unit, which was installed and seemed to work, but just to about 12.5 volts with no lights on. With lights ON the battery voltage started to dip below 12v, so there were more problems elsewhere.

So going down the checklist to consider for engine stalling problems:

Low compression/leaking valves

Incorrect ignition timing due to gap problems, dirt/corrosion on point contact faces

High resistance values on the spark plug cap

Incorrect coil primary winding values

Fouled spark plug/defective spark plug

A faulty ignition coil or wiring connections

Air leak at carburetor flange

Inoperative idle circuit/plugged idle jet

Spark advancer return springs weak or worn

Low voltage to the ignition system

All of the above were corrected, except for the compression issue.

Establishing some communications with the FL seller, it was determined that he had bought the engine from eBay, as well as the cylinder head, which was installed without checking the valves. Beyond the engine running issues, the transmission has a bit of a double neutral when shifting from 1st to 2nd. That could be some kind of issue with the shift drum or stopper, but the owner doesn’t want to spend a lot more money on solving the problems that have arisen. 

In having to refinish the rear sprocket cover, I discovered that the stainless steel Allen head screw was close up against the shift pedal on the upshift. I replaced the Allen head screw with a standard Phillips screw to give more clearance.

The best scenario, with it as-is, would be that the piston rings seat in and the valves find some improved sealing, as the miles accrue and the bike begins to be more useful and less troublesome. Sometimes, it doesn’t take much of a building error to spoil a bike project like this when one component step goes south or is overlooked.

In the end, I replaced the rear sprocket with a special order 38t unit from the Sprocket Specialist company. This reduced the rpms by about 500 in top gear. There was some rattling noises on the chain guard, which turned out to be because the inner portion of the guard was not seated properly in the raised guides.

A final test ride yielded good power, easy shifting for the most part and was easier to start that in the beginning. The plug check looked clean on both sides, but it still wanted to die off after 30 seconds if left unattended. The hot compression test was 120-130psi, so still below specs, but perhaps it will improve with some miles added to the engine build.

It was quite time-consuming and everywhere I looked there were issues that needed to be corrected or at least noted for the owner’s benefit.

It was here for a month… I wonder what’s next?

Bill Silver aka MrHonda


Friday, May 5, 2023

Mini-Trail with maxi-problems…

A local referral brought a nicely restored CT70H (4-speed with clutch) bike to me to “make it run.” The owner couldn’t get it started after installing an aftermarket CDI ignition system. I don’t work on these little bikes very often, but how hard could it be? Right?

Well, initially, having pulled the spark plug out and grounded it against the head, I could see what is typically the little wispy CDI spark jumping across the plug gap. CDI ignitions have a fast rise time and the sparks are not the big fat arc that you see with a magneto or battery ignition system. So, it is easy to miss the spark arc, especially on a little 10mm spark plug.

Knowing that I had a spark, but not knowing that it was timed right because the CDI module controls the spark timing, I went to the next step.. fuel. The bike had older gas that was infused with “stablizer” to keep it from going off. Age of the gas was not revealed, but it seemed like it was probably good enough to fire off a 70cc single. So, off comes the carburetor to check the jets.

As expected, the pilot/idle jet was blocked off with fuel solids. I have some tiny tapered jet reamers that will poke through almost anything in the #35 jet, so once the orifice was clear, the jet was reinstalled. The carburetor was a Chinese copy of the OEM CT70 carburetor with #35/60 jetting which was stock for a stock CT70. The float level looked off, so I reset it using my Honda float level tool, but it wasn’t clear if the setting was from the gasket surface, the base below the gasket or the raised flange around the outside of the bowl. I opted for the gasket surface but found out later that it is measured from the carb body itself.

Putting the carb back on, I noticed that the stack of the gasket and insulator were reversed when removed. Eventually, I had to remove the manifold and put it on a sander to flatten out the gasket surfaces. The mounting bolt holes in the manifold were “enlarged” apparently to compensate for the replacement cylinder head mounting bolt holes being a little bit “off” from what the manifold was made for.

Then, petcock started drooling at the lever so that needed attention. The dual fuel hoses were pinched off and the lever was removed. The back side of the lever was uneven, so that was smoothed out and the parts were reassembled with no further leaks. The float bowl gasket was typically swelling up so it was washed in soapy water and left in the sun for a while.

Once everything was reinstalled, the bike fired up on the second kick with a full choke. So far, so good… or not. The bike ran okay at idle, but the first test ride yielded some part throttle misfiring through the mid-range and towards wide-open throttle. Using the choke, it picked up power with about half the choke closed, indicating a lean condition. I tried a number of needle clip positions, but it seemed to like the richest position for mid-range and top end, but you could hear it “8-stroking” just off idle and the plug was sooting up. After quite a while of messing with settings and texting to the owner, he reminded me that the fuel cap had a variable vent feature which was in the OFF position. The cap seemed like it might have been an aftermarket copy as the vent passages were somewhat restricted, so I spent another 10 minutes massaging it, so that the vent function was fully operational.

As the text conversations continued it was revealed that the engine was not 70cc but 88cc and more variables came into my head as to what was happening with the carburetor jetting. The 88cc kits on eBay included a performance cam, which will upset stock carb calibrations to a certain degree. All signs were that it was running lean, so I reamed out the main jet to about #70 size and the bike began to pull strong through the mid-range and WOT but was still too rich off-idle. Moving the clip up to lower the needle made the bottom-end leaner but then the mid-range went lean. Looking carefully at the needle jet, it appeared that the top edge was not beveled like most of the ones I have seen. I have run across this problem with Chinese-made carb kits and it appears to have a big effect on how the fuel is distributed coming out of the jet edges.

As an experiment, I had some aftermarket needles for CB400F carbs, which are a little longer but thinner. I clipped it as lean as possible and tried it out. The power improved in the mid-range and WOT but it was still too rich off-idle. I contacted the owner who told me that he had three more carbs, including an OEM that was going to be rebuilt, so I asked him to bring it all to me for evaluation.

In the midst of all this testing, an oil leak developed at what seemed to be the shift shaft, but with the left side covers removed, it was coming from the big o-ring that surrounds the ignition/charging system mount plate. I had to pop off the rotor, remove the two mount screws, and borrowed the o-ring from the OEM plate to seal it up. While apart, I noticed that one of the CDI coils appeared to be rubbing up against the inside of the rotor, as there were witness marks and a bit of metal debris floating around inside. I tried to reposition the coil slightly and replaced a failed flat washer that held it in place. Like the movie, these bike projects can become “ The never-ending story” when the combination of OEM and aftermarket parts collide in a vintage Honda.

Certainly, when you install a big bore piston kit on a stock cylinder head and manifold/carb setup, the airflow needs are going to be increased quite a bit. The compression readings were about 160 psi, not unusually high considering the engine setup. The intake manifold mounting bolt holes were enlarged around the bottom portion as if there is a mismatch between the head and manifold dimensions for some reason. A lot of this information would have been helpful when the bike was received, rather than learning mid-repair cycle after hours of fiddling with what should have been an easy repair job. Oh, in the last visit, the owner felt that the gasoline might be a couple of years old, but had some stabilizer added when parked!

As a final attempt, I put a #65 main jet in one of the new replica carburetors, reset the float from 22 to 20mm, put the stock needle in the middle notch, and bolted it all back up again. I did, as an experiment, use a large drill bit to flare out the edges of the needle jet in hopes of improving the fuel delivery flow.

The bike started quickly (with a new spark plug installed) and pulled well at medium driving speeds, then with WOT it seemed to pull cleanly to whatever redline was at a thrilling 30 mph. Hopefully, the owner will approve of the current setup and it can go back home. With some fresh gas, it should be good to go again.

Bill Silver

aka MrHonda