Hi
i recently changed my 2011 klx250s front sprocket to a Moose racing 13T.
but i noticed a strange noise come from the front sprocket, and it's only appear when i acceleration. its gone when gas off.

is this normal?

 

I noticed more noise on the 13 tooth too, its just that the chain has a smaller circle to wrap around. Its really as normal as it gets. I've been running the same 13 tooth fron for about 12,000 miles and it still looks new.

 

What deej said. Your bike sounds new enough that this is probably not an issue, but to be sure, check to make sure the chain rub blocks closest to the countershaft sprocket and swingarm pivot are not ground down. The smaller sprocket will put more wear/stress on those rub blocks, so keep an eye on them.

 

The stock sprocket have some rubber, it must eliminate some noise.

 

I switch between stock and an aftermarket counter sprocket and have never noticed any different noise from them.

 

The newer bikes do not have rubber. Just the gear.

 

Yes, I think it does. I switched from stock 14 w/ rubber to a 13, and 15, and the 13 & 15 w/o rubber were a little noisier than the 14...until the rubber completely filled with mud and crud and was removed from the sprocket.

 

Same here

 

What rubber chingas? We don't need no steeenkin rubber chingas... didn't see anything like that on there. I just remember that freekin nut needing a decent impact to take it off.

 

Here's a pic of the rubber chingas before plugged with mud and removed.