when i go to take off i hear a thud/knocking sound.
i'm pretty sure its not the engine in anyway, to me
it sounds like a clutch or tranny problem. she's got about 31000
miles on her. it started doing this about a month and a half ago
and then mysteriously went away and now is back,
just wanted to see if anyone had any ideas or had been thru this before..
thanks
shawn
(fastcbr)

 

What condition is your chain in?

Sounds like the chain has a tight spot in it, and could be stretched.

 

I agree with checking chain and/or sprocket condition as well as checking the chain for over-tightness.

Could also be the way you're engaging the clutch.

On my FZ1 I sometimes get some clunking when I take off from a stop. This happens when I engage the clutch a bit too quickly and the gear ratio has not yet matched engine speed so there's a bit of "lugging" that occurs.

 

Good call, I always assume that everyone knows how to drive/ride properly... It could very well be that he's lugging on the clutch (not enough gas, release clutch too quickly)

My CRF450R is very susceptible to this, being a thumper.

 

thanks guys for the info, it was the chain. i tighten up the chain and
lubed her up good and the knocking has stop.
you guys are a savoir!!!!\
thanks again
fastcbr

 

If the chain and sprockets are old and in bad shape you should look at having them replaced.

If your chain breaks it will take out your engine casing and possibly the back of your leg with it.

Not only does a set of new chain and sprockets look pretty, you can go up 2 teeth on the rear and make your bike much more fun to ride

 

thanks man,
i'm waiting on the new sprockets and chain now

 

Don't make that chain too tight.

I usually run anywhere from 2 to 3 inches of slack....enough so it barely starts to contact the underside of the swingarm when pushed up.

That's what I like to call "trackday tight".