The airplane in my Avatar is an SR Batteries 1/3 scale Eindekker. 106" wingspan if I remember correctly. I powered it with a Honda GX31 four stroke. It had enough power to loop from level flight, but just barely. I ran the engine inverted and had no problems other than in storage, the oil would gradually run down and soak the plug, so I stored it with the airplane upside down and the spark plug upwards. The Honda engines have a special oil sump/system and can be run inverted; with the caveat being my above noted problem.

Yes, the Stihl Four Mix engines run oil in the gas like a two stroke, and have no oil sump/crankcase. What amazes me is that they are quite powerful for a four stroke. But they still have that cool four stroke sound, and fuel economy. I have a 36cc Stihl Four Mix all converted and "squirreled" away. Hopefully one day it will find a home on a Fokker D7. Should be a great combo!!

AV8TOR