ah one of the good ones!. well they work exceptionally well. they run a 2 stroke air cooled engine . bore of 87mm and a stroke of 85mm , overall displacement = 487cc. engine is classified as a torque induction.with a compression ratio of 7.0:1 .its fueled through a huge 38mm carb mikuni 38ss/5x6-00 , runs a main jet of 440 (wow) and a pilot of 50.these engines are tuff as long as you are anal on the maintenance. run excellent fuel, top of the line 2 stroke oil, and a well recommended base oil. always keep the air filter clean and heavy oiled , good idea to have a spare on hand so you have a clean one every ride.
hoped this helped you if so please accept, thank you.