While doing a little research on an entirely different matter, I wandered onto the Subaru 24.5cc and 33.5cc micro 4-stroke engines. To make a long story short, I determined that these little engines are the basis of the rather pricey Fuji 4-stroke engines sold through Tower Hobbies.

Subaru link: http://www.robinamerica.com/engines/...so?Class=Micro

Tower Fuji links: http://www2.towerhobbies.com/cgi-bin...?&I=LXJDJ5&P=7
and: http://www2.towerhobbies.com/cgi-bin...?&I=LXJDJ6&P=7

These Subaru engines have been around for a while, but are not very widely distributed. The 33.5cc engine has a suggested retail price of $249.99. They do show up on fleaBay now and then, often built as a pump unit or on a Zooma go-ped type scooter.

Has anyone here tried doing a conversion of one of these Subaru engines? I think they would have potential (Fuji evidently thought so anyway). The larger engine is rather over square with a 39mm bore and 28mm stroke, which should help in the top end and relative weight. Though not able to run continuously inverted, the Subaru engine does not have the extra weight of the Honda mist type oiling system.

Search as I might, I can find no other conversion info other than the existance of the Fuji commercial conversions of these engines.

Has anyone out there tried to work with one of these Subaru engines?