Kostas 1:

I don't know about RPM's, etc., but I do know that my .61 pulls my Hangar 9 Alpha 60, WS 70 1/2" very nicely. I took off the 3 bladed prop
that come on the trainer and I am now using a 11 x 7 APC and it pulls it even better.

This I can say, It is one of the most dependable engines I've seen and rarely needs re-tuning at all.

I have about 5 gallons tru mine, to date. No trouble at all.