Sled runs very stong, but can't get past 90 MPH (800). Drive along all day under 90MPH and its perfectly fine. As soon as I try to go past 90 MPH, feels like it blows a belt, and basically falls flat on its face. Engine still revving freely, lights do not dim. As soon as this happens I let off the gas and the sled kicks back in. I can run WOT up to 90 MPH and no problems at all. But once I get to 90 MPH I have this weird problem. Thought it was the clutches so changed both springs and this didn't solve the problem. Opened the chaincase and everything appears fine. A good example is it feels like a governor in a car. Anyone?