Hello,
I bought a 1994 CBR 900RR last week and am pleased with it, however I am concerned with a noise it makes in 1st gear while pulling away from a stop. The noise sounds like a clunk or click multiple times (3-4) at maybe one second intervals, not evenly spaced. It seems to happen just as I let the clutch out fully, however I cannot say that it has anything to do with the clutch. I did try leaving in second gear from a stop and the bike made the same noise at about the same speed. It doesn't hesitate or jerk at all when I hear this noise but I'm concerned because it almost sounds like a gear meshing incorrectly. I thought maybe the chain was loose and was banging on the swing-arm? I'm pretty sure it's coming from the drive-train somewhere and once again it does seem to be speed sensitive. I do have a lot of lash in the drive train. (the bike has 30,000 miles) I was thinking maybe the rubber cush pads in the rear hub were worn and would explain that. Any info or thoughts on what to check would be appreciated. Thanks
Zach

 

Not an expert by any means, but I would check the chain first and make sure its not getting kinked and has the proper slack. Put it up on a stand and roll the rear tire by hand and see if you can duplicate it.

If that's not it, then I would check the crush pads. Easy enough to pull the rear wheel and see what kind of shape they are in.

Keep us posted on what you find.

 

Well I got the back wheel up and turned it around. I was unable to duplicate the noise, but I did notice that the chain had some tight spots and that there was a bit of slack in the transmission. I could turn the sprocket on the countershaft 1/20-1/16 of a turn before it would catch and I was wondering if that is normal, or how much lash the transmission should have. I was unable to duplicate this occurance without the bike on the ground but when I rode it again I heard the noise. It sounds like what a one way clutch would that is stripping out. really high pitched screech. Maybe a bearing? It seems to get better when I let the bike warm up but it is still there. (it's about 35 degrees by us) any more leads would be appreciated thanks.
Zach

 

Does it do it in any other gears? Could be a few teeth are missing on 1st gear in your tranny. Try taking off in 2cd see if it still does it.

 

I did try starting out in second gear and the bike made the same noise at about the same speed.
Zach

 

Good news guys! I took off the rear wheel to check the cush drive, and noticed there were little mashed chunks of metal, about half the size of a penny, in with the rubber blocks. Upon further inspection the bearing spacers were disintegrating. Anywaythe bearing on the sprocket hub was shot. I hope this is the problem and will tell you how it goes once it is replaced.
Thanks for all ofyour input,
Zach