I am currently flying a OMP Yak 54 at 7.5 Lbs. with a Webra 1.20. I cannot imagine a better combination. I am using an 8 Oz. fuel tank and commonly land with 3 or 4 Oz. remaining after a ten minute flight. In over 25 flights now have never used full throttle. With the Bisson sport muffler if there is a 4-stroke in the air you can't even hear the Webra running, probably because it is never running over 5 or 6 thousand RPM. I am strongly considering a Funtana 90 for this engine if and when I dork the Yak.