Hey guys,

You all have helped me before and I'm looking for some wisedom again. I have a 99 F4 that's making noise that I believe may be transmission related. The noise is a kind of knock sound (no, not a rod knock) that happens only when going into/in gear at very slow speeds (less than 10mph). It happens in both first and second, and it doesn't happen once I am at speed or decelerating. It is specifically low rpm, low speed. I thought it was only first gear as well, but then repeated the noise rolling out in second. It'll make this knock from down by my feet maybe two or three times at the most before stopping.

Any ideas? If you need anymore info let me know, you've only helped me solve similar problems in the past. Thanks!

 

Are you sure it isn't the cam chain tensioner?

 

Does it feel like it is in the rear wheel hub?Unless I am having a brain fart, it sounds like those doohickys in the hub may be acting up.

But don't go taking anything apart because I wrote it, I am basically retarded and I may be thinking of an outboard engine and not a bikes rear wheel.

 

I was thinking CCT possibly, don't know about that rear hub.

I will add that this tends to occur only when warmed up to normal operating temp. Any colder and I have yet to have it.

 

I think fish frier may be talking about the rear cush drive, however, I am more inclined to think that you know where the sound is coming from and it is around the tranny. It could be the dogs, however, it is unlikely. At low speeds it is even more unlikely that it is the shift fork.

Can you further describe the noise. Does it happen under power, when the clutch is engaged/disengages, coasting, etc.

 

I just read that it only happenes under acceleration. How much acceleration? Can you give us a RPM v. throttle position estimate?

 

It never happens with the clutch disengaged. And it ONLY happens when I first start out, assuming that I would be able to hear it over the exhaust noise. The less throttle I give it, the more likely the noise will occur. It does not affect my acceleration (no hiccupipng). Very low rpms, like less than 3K, but I can't reproduce the noise once I've got it rolling, regardless of speed or rpm.

 

TTT

 

Clutch pack problem? What about it happening when you were leaving second? Is it becoming more apparent as time passes, going away, or starting to happen under different conditions? Can you post a vid since it happens at low speeds?

 

I can't do a video, the exhaust is louder than the noise when I'm recording. I don't believe it's a clutch pack problem either. If it was, I'd expect a stumble or hesitation or chattering of some sort. I have smooth power throughout the sound. It seems to happen most often (almost every time) when the bike it at operating temperature and only when I roll out. Both first and second produced the same sound.