QuestionI have a GSXR 750 with 13000 miles on it and I just resolved a situation with the jetting. The bike had been running rich and fouling plugs, (half a jet kit from previous owner). After getting the bike back from the dyno I noticed an engine knock and after having it checked out by all 3 mechanics there the concensus was, the sound was not rod or valve knock, it was located either at the starter clutch location or cam chain tensioner and a 75% probability it was a bad starter clutch.
Heres the problem: The engine knocks once per revolution only while under load (1/4 throttle or more, less noise at full throttle), in any gear, predominently when the engine is running between 5000-8000 RPM. The noise does not increase in severity, loudness, or pitch, as RPMs go up. There is no knocking under coasting, idling, or free reving the engine. There has been no loss of power, stumbling, hard starts, oil burning, coolant loss, slipping clutch (new clutch with 800 miles on it), or anything else bad.
I think its either the starter clutch, chain tensioner, or something in the clutch pack, but your input would be greatly appreciated. Because as you know, any knock is a bad knock.
AnswerHi Chris.
My grandfather had a saying: "If two doctors say you're sick; Lie down."
That saying really applies here. You've had 3 mechanics look at the problem and say that it is one of 3 things, so start with the simplest first.
Adjust the cam chain tension. See if that fixes the problem. If it doesn't, then move to the next simplest, then the next after that, until the noise goes away.
After that, the only other possibility is that there is something loose in the recently replaced clutch assembly.
Let me know what you find.
Good luck.
FALCON
