Have an AAEN clutch kit and roller clutch on a stock 2000 SCRAMBLER 500 4X4. It came with a red primary spring and 55g weights. The roller kit has a 44/40 helix with stock spring.My buddy put a EPI kit in his and he smoked me on top end. I've tried different spring settings and springs in both clutches plus different weights.I just get the same results.We switched kits and I beat him on mine. Called AAEN they said thats the kit they sell for that model. For the price I would have gotten the EPI kit . Just wondering if anybody has this setup and if it works

 

I haven't received my EPI kit for my SP HO, but EPI is the way to go!

I will be trying the AAEN muffler setup on mine too.