Hi MM,
A few things could cause hot running in an aircooled - Are the cooling fins clear, and is the air cooling intake unobstructed? (about the easiest to check)
Is it smoking black or still running clean exhaust under normal load? Black smoke means "running rich" could be caused by clogged air filter or inlet (Easy to check) or even injector timing that is a touch out, maybe even valve clearances a little on the tight side... All quite easy to scope, and pretty visual...(Injection timing could be a tricky one if you are new to it though)
Is the exhaust pipe perhaps clogged with carbon buildup? Also an easy but dirty job to do in a confined space...
If you could give a few more possible symptoms, such as hard/easy starting by hand or electric starter, smoke from the exhaust and colour of smoke, ie blue/black/grey and when it smokes ie under load/after warmed up etc...
Any other information such as easy or difficult to turn engine over by hand with a crank handle all might help one of the guys to point you in the right direction... Rather too much info than too little...
Regds
Ed
