Recently purchased a 2003 Trail Boss 330. I have noticed a popping/ knocking sound that seems to come from the transmission area. I have noticed that the front sprocket has some play in it. Anyone seen this or know what the problem is? Thanks.

 

It could be a worn sprocket, a bad link in the chain, or even a loose chain that is skipping over the sprocket. I've had all three things occur. I'd recommend getting the back tires off the ground safely, and running it while you watch that area.

That'd be a good start, IMO..

 

Thanks, 400x. I got it off the ground, but it doesnt make the noise.I guess not enough tension without the weight of the rider. I was leaning towards sprocket (at least hoping not transmission). Anyway, a good place to start.

 

i have a 96 425 magnum and i had a similar noise coming from my transmission and it was the sprocket for the rear chain. the way i knew right off it was the sprocket was that i looked at the chain where the sprocket was and could not see no teeth on the sprocket, they where worn down that much.

 

If you replace sprockets you ned to replace chain also, old chain will wear out new sprockets.

 

Front sprocket appears to be the cause. Thanks you guys for the help.