My buddies scrambler 400 has no power, he broke a belt and put a new one on now it won't take off good. Once you get it going it has power, my thoughts were low compression or somthing wrong with the belt.

 

I think a more likely cause is that he wore a groove into his drive or driven pulley, possibly from lack of cleaning of the clutch surfaces or from burning a belt. This causes your clutches to engage the pulleys at the same RPM, but they have less surface area of the belt to hold on to. Instead of grabbing your belt on its tappered sides as it was designed to, it grabs it at the flat side of the belt which is a smaller surface area. When you first start out, that is when you require the most grip on your belt to get things in motion and that is why it doesm't launch hard-it is likely slipping slightly.

 

Ok I'll tear it apart and inspect them. I don't see how it could be possible for a rubber belt to wear a groove into a steel clutch?

 

if the scram was running well and then turn bad after putting a new belt,it is probably the belt deflection not dialed-in for the secondary clutch,is the quad engage and go(foward) at idle?
always set the proper belt deflection after each belt test...