Started my 2002 f4i, which has 9k miles, and immediately started to hear a clunking/rattling noise on the left hand side ( riding position) at idle. Rev'd the engine, the clunking sound got louder. Took a drive down the street and the clunking was really loud. Engine seemed smooth, just noise.

I shut down the bike, let it sit for a bit. Restarted, and the same noise remained.

Went inside to grab tools, came back out and started it again, the noise was gone. Took a ride down the street and it sounded perfect.

WTF could it have been?

 

Bueller....

 

If you are certain that the noise was coming from the left hand side then I would think it would be the primary gears otherwise it could have been the CCT. Glad to hear the noise has now gone and I hope it doesn't come back! Let us know if it does.

 

Rode about 100 miles yesterday and no noise. I do need my CCT changed and am familiar with the sound.

This was different though. It was on the other side of the bike, and started immediately upon starting and made the sound through idle, as well as through all rpm's.

Im starting to think something wasn't seated and it went back in place...but Im hoping someone has encountered this and may shed some light on specifically what was causing it.

 

Hi. Any chance that one of the cylinders dropped out momentarily even though the engine seemed to run smoothly? A three cyclinder is smooth so if one of the middle cylinders had stopped it might have caused the clutch to rattle, although it is on the right hand side it may have transferred the noise through to the left. Just a thought! Hate mysteries don't you? I'm having a problem with a friend's computer that's driving me mad too! LOL!