I noticed under load or hard acceleration the bike would sputter or cut out. It has 1900 miles with 30" mud tires. It runs perfect otherwise throughout the rpm range and at all speeds. Changed coil, plug and wire. Running pure gasoline. I flipped the display over to the tach and put it on a hill to diag and it seems to cut out at 3600-3800 rpm every time under load. Am I looking at clutch/belt problem or should I be looking in the carb? This is the first and only auto trans I’ve ever owned.