650/X-2 650sx idles fine, but accelerates extremely slow

[bonsy17]

My 650sx has no power. The ski starts and idles great. Once you get on the gas it accelerates extremely slow but will eventually reach a reasonable speed. So far I have checked compression (155 psi each cylinder), cleaned the carb and replaced reed gaskets (had extras laying in the garage) the reeds looked good, checked fuel lines and tank check valve, and the fuel line from the fuel pump has a solid pulse of gas coming through it. The impeller looks like new. Does anyone have any ideas on what this could be?

My next thought would be to make sure there is no restriction/leaks in the exhaust and test the fuel pump from a good running 650.

Any help would be greatly appreciated!

 

[stuckmoto]

I had the same issue recently, swapping out with a new impeller did the trick. I know you say the impeller looks good but, how tight is the clearance between it and the wear ring?

 

[bonsy17]

Thanks stuckmoto, After taking another look at it tonight when you mention the prop there is a spot where a rock must have went threw. I will try and swap it with another prop this weekend.