whats that noise ?

[greatmoorred]

My engine or gearbox, or possibly, clutch has started making a sort of rumbling/grinding sound when i come off the accelerator.  It doesnt sound too good and i was wondering if anyone on here has any ideas what it is.
Thanks.

[PitterB4]

How's your chain?  They can get noisy when they go.

[sirdarkheart]

Yeah I would say it is the chain. make sure the slack is okay and that the rubber piece the chain lays on where the countershaft sprocket is (slider), is not worn down. if your chain is loose or if your chain is shot it can get loose when you roll off from a hard acceleration and that would cause it to flop around like crazy grinding on whatever is around it. Hopefully, it's not a bolt that came loose somewhere in your engine block. That will be like finding a needle in a haystack.
:D

[interfuse]

+1 on the chain. When I tried chainwax I thought my motor was about to pop. I had a metal on metal ringing soung going on whenever I released the cutch. I switched back to real lube and the insane ringing went away. Phew. Did i mention I don't like chainwax???

[Tundrahog]

I have somthing similar, except is happens under acceleration.  I'm sure it the chain, because it'll go away for a few days if I spray some lube on it, or clean and lube it.

Is the chain going bad, or do I just need to keep spraying it once a week or so?  The chain was a little loose, I fixed that, now it's in spec.

Bike's got 7500 mi on it, and i don't ride it that hard Honest!!!  

Oh and it's a B12, sorry to invade, but I figger'd the principle is the same.

[greatmoorred]

Ok, thanks guys, i'll have a good look at the chain.
I cleaned it with WD40 and then gave it a good lube up with chain lube, but i might switch back to standard oil.