you know , i have no idea and i cant find anyone that knows. mine is used and i dont know if im going to mount it on my plane
because you cant get any parts for them an id hate to go ahead and redesign my fire wall , then have it crap out on me.
its got some crazy mount plate on it . i like the rear exaust , and angled down carb , size wise it fits my tempest really well.

i havent set up a test stand for it , dont even know if it runs well.

If zenoah only made the G 45 OR 62 with rear exaust

may go with a US 41