Clunk when revving 900 Fireblade from idle?

[Stu900rr]

Hi all,

I've recently bought a 1997 Fireblade 900rr. It had the usual cam chain rattle when I bought it, so I've fitted a new CCT and the noise has gone.

However, I've noticed that when I rev the bike from idle (and from idle ONLY) in neutral, I can feel like a clunk through the seat. There's nothing loose under the seat, and it almost feels like it's coming from the engine but reverberating through the subframe and into the seat, which is why I can feel it there.

Any ideas anyone? I'm pretty stuck.

It's worth mentioning that it doesn't clunk like that when revving from anything above idle, and is much less when I rev softly rather than a quick blip.

Cheers, I hope that description was clear enough.

[jjdugen]

Clutch basket. They all do that, sir, with a few miles on them (and some cack-handed wheelies).
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[Stu900rr]

Cheers for replying!

Ah yes, that would make more sense than crankshaft bearing problems, like some have suggested. It runs sweet as a nut, it's just that clunk... which does come and go, and is less frequent when the she's warmed up properly.

I'll get a mechanic mate to have a look at it tomorrow, but thanks for the input so far

[Wafer_Thin_Ham]

My money is with what Chalky has said. Bet if you pull the clutch lever in (still in neutral) and do the same thing, your vibration will go away.
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