( 97 SX 600) Even with the stock 0,75 track I seem to hit a wall at 80 mph with this sled. Will not go any faster, else than on a stand. Reeds looked ok, carbs are cleaned, gearing is stock. Right now, my venture 500 will run just as fast. Tried with the worn clutch that sat on it and the set up for the venture. Still, same speed. What could be wrong?