Finally got to fire up the 50cc Twin and was very impressed. Ran 4 tanks through it with a total run time of about 50 minutes and a little under 1/2 gallon consumed. Temp was 26*F, 60 ft ASL. Fuel was 89 octane (10% ethanol, of course) and Pennzoil Air-cooled low ash 32:1. Prop was TBM 21x8. Reliable idle after first 2 tanks was 1800 RPM, high 6580 RPM. Nice running engine with outstanding transition, RPM's probably held down a bit by my jury-rigged muffler extensions, made from some PTFE (Teflon) elbows and an old wing tube. Henry advised that the 2-into-1 header won't be available until sometime in March and I didn't want to cut the cowl for the stacks, hence the modification...

Video: http://www.youtube.com/watch?v=RNg1F...e=channel_page