Never saw a two stroke case that hot, but I'm not an auto clutch guy. It must have been slipping a lot for a long time. EVANS waterless coolant is a good product where boil over is a problem.
Keep in mind your rekluse clutch slips its self on the bottom end. Just because you don't have a clutch lever doesn't mean the clutch is not slipping. Might cause an overheat issue if run at low rpm for a long period of time.
