Just got my first CB750. Love the thing, rides like a dream but I started having this problem just this week:
After riding on the highway for a while at 5.5 to 6k RPMs, for maybe 20 - 25 minutes I get off the highway and am back to the surface roads. I slow down for red lights / traffic. If I slow down enough to coast in 1st or 2nd gear (or stop at a traffic light) when I again accelerate I get a very unfortunate clunking sound that lasts for a few seconds.
It sounds similar to a clutch plate trying to engage, but the ride is fine. What I'm reading online - and seeing in diagrams - suggests that it's coming from the vicinity of the cam chain. It is coming from the left side of the engine, but all the diagram shows where I thought the sound originated is the A.C. generator. And I doubt it's that.
Anyway, I'm sure someone else has had this problem and maybe even posted about it here... any help? This is my new baby and I want it to survive a while.
you know, not many here have 90s cb. I would suggest getting the manual from the repair manuals section.
However, it kinda sounds like a bearing in the tranny might be dying.
It would be really hard to say.
I will see if I can dig up anything.
The ride IS the adventure. The destination is just to get gas!