21K motor, alot for the CB77?21K motor, alot for the CB77?I recently picked up a bike with around 21K on the clock. It seems to run fine after sorting the carbs and fixing a stuck clutch. I am wondering what constitutes a high mileage motor on these bikes?
My CB77 showed 30k miles, when I bought it in '08. The gearbox bearings proved to be a little noisy, although not excessively. The k/s pawl was totally shagged and the little ends rattled quite badly.
Other than those obs, the rest of the motor was very sweet. The powerplant is currently undergoing major surgery, albeit slow and sporadic!
Mine had 18,000 miles on it when I took it apart. Yes, it had a cylinder that had seized, but everything else showed "normal" wear. The engine was/is okay, the cam lobes are fine, the bearings all okay, however the cam chain roller and tensioner roller where worn out. The primary drive tensioner's roller was NOT worn, however. In the transmission, the 14mm shouldered bushing was worn, as was the kick start pawl. Everything else - shift dogs, shift forks, bearings - were okay. The clutch was NOT stuck and it appears to be fine (I've not measured the plates, however - just eyeballed them).
I'm thinking that sans the seizure, my engine could have gone considerably further before it needed attention. In my opinion, the engine is sort of a dichotomy. In many ways it's way over-engineered and over-built, but then it has those niggling parts that wear quickly - 14mm bushing, cam chain roller/tensioner, and kick start pawl. Perhaps with careful attention to maintenance guidelines and frequent oil changes (with the proper lube) even those items would soldier on for quite some time. It's quite a well engineered piece of machinery! 1965 CB77 305 Super Hawk
1989 NT650 Hawk GT 1981 Yamaha XJ550 Seca Mine has 66k kilometers, I doubt it's ever restored, thing just runs great. Use's no oil and everything just works as it should. Little tappet noise but that's because I run on modern -normal-(thin) oil.
One time I took it to 140km/h with no problem. ( I took it easy because it's an old bike, so he...) , put I got plenty of power left. Did some highway miles this summer with no single problem, the bike is like new, everything just works. Start with no problem, no 'cold blooded bike' here. When it starts, warm or cold, it's just ready to go. I only choke on start (when cold) , when the bike runs the choke goes off imediatly. Maybe just for fun I will check how it start when it's freezing, I doubt it will make any difference. 'Of course I've already taken a very modest position on the monetary system, I do take the position that we should just end the Fed.' - Ron Paul
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