My 800 Etec has a 'flat spot' in the throttle response. When accelerating smoothly from low rpm to high, the tach will hit about 7000rpm and basically stop even though I continue squeezing the throttle. The throttle moves a significant distance without any response from the engine, then suddenly the engine jumps to life and runs to 8000rpm. Have rode two of these sleds and both have this issue. Anybody have any similar experiences or fixes? Thoughts?