I have this engine mounted on a Great Planes 120 Stearman. None of our club members reconize it. The head is tapperd, has rear exhaust, magneto & a spring recoil starter. My guess is a Quadra 42.

Bme?

Will check their site.

It most likely is a Quadra (U.S.engine).

its a quadra 42

Thanks. That was my guess.

its no Quadra its some ones Weed eater conversion has wrong crank case to be a Quadra

Whatever it is, it screams & flies a Stearman with authority.

Looks like either a zenoah or a quadra to me