It started last November, pushing out a CL77, then taking in a CB750 which had been treated to an 836cc kit, but someone forgot to get one of the wrist pin clips all the way in and it ground a groove in one liner. In the background, I was piecing an early CL77 together from misc bits (separate story coming).
Then, there was the return of the blue CL175K3 that caused a lot of headaches in the beginning, then has come back for a mysterious oil leak and poor running conditions. No mechanic wants to have comebacks return the shop, but this came back with intractable problems with the suspension and carburetion.
I had a 1963 CB77 dropped into my lap which had a reported replacement top end due to piston seizures but was never run after re-assembly. That one required pulling the engine again, as the shift drum had rusted the forks in place, due to inactivity for many generations. That one was a pretty nice original bike but needed the usual tires, cables, battery, carb overhaul, tank sealing and various electrical repairs. Thankfully, that one sold to a local enthusiast.
The CB750 had a removable frame section above the engine so I could remove the top end without pulling the 175 lb engine assembly from the frame. The bike was spewing oil out of the #3 cylinder as well as a big leak at the crankshaft seal behind the ignition system. The cylinders had to be shipped to Cycle-Xpress in Wisconsin for liner replacement and boring, plus fitting new pistons to the rest of the cylinders. Slowly it came back together but then the carburetors wouldn’t fit back onto the cylinder head spigots. The chassis was late 1969-early 1970 and the carbs were 1975. After trying to force the carb rack back on with new copies of the manifolds that were on the bike, I discovered that Honda made revised manifolds for 1971-76 bikes. They solved the problem at a cost of $150 for the set.
A KIA camshaft seal has the same dimensions as the OEM crankshaft seal on the 750, but without the ridge that normally holds the seal in the cases. I pried the old one out and installed the new one from the outside. Otherwise, you have to split the cases to install the OEM seal where it registers with a groove in the upper and lower case halves.
There were more problems with just changing the oil and filter. The drain plug washer was missing and the old oil was diluted by some kind of miracle engine fluid that the owner thought might fix the oil pumping out the pipe. The oil filter was missing the flat washer that sits on top of the spring that pushes against the oil filter element. The exhaust system was a fabrication set that had two pipes anchored to the footpeg bolts, but the inner pipes were held to the bike and outer pipes with hose clamps! Then the battery died and I had to push it 6 blocks back home again. It’s just one thing after another, it seems.
The CL77 bike came with the wrong rear wheel and swing arm and missing lots of parts. The old tire on the replacement wheel was a monster 4.00x19 rock hard chunk of rubber. I was able to eventually pry it off and spoon on a new one, but when I fitted the wheel to the bike the wheel locked up when I tightened up the axle nut. I had missed the fact that someone had robbed the hub of the inner wheel bearing and the spacer. I rebuilt the engine, which came with a CB77 cylinder head/tach drive and then discovered that the crankshaft was also from a CB with the oil hole for the starter clutch. There were damaged gears and it needed the full transmission overhaul with replacement bushings. Eventually, it came back to life and sounded pretty good, but still looked a bit tatty.
The CL77 clutch was dismantled during engine repairs and inspected with all parts apparently correct for the engine, but the clutch pull was a 2-handed affair, so was inspected once again and some softer springs fitted, which fixed that issue. There were many problems with the chassis wiring, including a dead headlight bulb and then the tail light needed to be replaced with a different bracket. The fender was painted but not cleared for a good ground path, so more work was needed to remedy that. Finding a front fender for CL72-77s became quite challenging during the process.
The CL175 was reported to have a little oil leak, but the owner had cleaned it off before it came back to me. I had to guess where it might be and reseal the left side cylinder head cover. This bike had been running some aftermarket carburetors as the original ones were fitted with some aftermarket parts that prevented the bike from running properly. The left side was the biggest headache, despite having the carburetors off numerous times for cleaning and inspection. Eventually, I checked the #90 main jets on both carbs and the left side and finally determined that someone had drilled out the jet to about a #105 size, which caused all of the plug fouling. Fitting a proper sized main jet finally fixed that issue.
Then, there was a problem with the front end. When the forks were removed to allow the new headlight ears to be fitted, a bit of slack was noticed at the bottom of the forks, as if the fork springs were too short. I pulled the right side off and wound up fitting a ground down intake valve spring into a short spacer to put pre-load on the fork assembly. The bike had suffered some kind of crash damage that caused the forks to be out of alignment, making refitting of the fork legs difficult. On top of that, the front brake started to cause the front wheel to dive to the right under braking. Inspection showed that the primary shoe was contacting the drum fully, but the secondary shoe was not. The brake plate was checked and the shoes cleaned and synchronized again, but nothing influenced the brake to behave normally. Finally, the bike was sent to a frame shop to check out the frame alignment and perhaps replace the steering stem.
The battery wasn’t charging properly, so the engine continued to run roughly. The OEM style rectifier was replaced with a solid-state unit, which seemed to improve the battery stability and thus the coils were getting 12v on a regular basis. Then, there was a problem with the replacement gas caps not venting properly and the petcock not feeding the carburetors equally.
Diagnosing and repairing these continuing problems takes at toll on your psyche. When you have worked on Honda products for 50 years, but suddenly everything you attempt seems to fail due to some mysterious maladies that are hiding in the background, you begin to doubt your sanity or ability. Obviously, problems such as these eventually have a resolution, sometimes requiring replacement of what seem to be good parts and doing a lot of questioning your mind about what is missing to cure the problem.
At sometime, I will hang up my wrenches, but even though I am 76 years old, my overall health is good, so I will continue to try to sift through the clues and come up with some resolutions that bring the bikes back to something close to what they had experienced after driving off the showroom floor.
It would be great to have an intern or understudy to absorb the experience and information that I have floating around in my head. I have spent many hours helping on various Facebook forums for various models, as well as continuing to supply my restoration guide downloads for the 250-305 series models. Hopefully, what I have shared is taken in as fact in most cases to those who are generations behind me and share with their peers and any upcoming enthusiasts to take the knowledge forward into the future.
Bill Silver aka MrHonda
www.vintagehonda.com 01/19/2025
im sad I live so far away, and about to move farther, I'd take up that intern position. However? what 76 year old wants a 60 year old intern. We need to find a youngster to pass this knowledge down
ReplyDeleteBill. dont retire without first getting an intern to learn your knowledge. We are losing all the people who know these machines as well as you do. I wish I lived closer to San Diego. I need the white Dream 305 clutch / shift problem solved. Do you have a good clutch assembly for a 1967. ?? when I ride the bike she shifts fine. but very often she gets stuck in gear and I have to upshift first before I can get down to first or second gear. you mentioned possible wrong clutch parts used. shifting up and riding is perfect. its usually downshifting.
ReplyDeleteHear ye, hear ye.....new retirement age with Honda Circle of Safety is 100 years. Easy does it.
ReplyDelete