bme 3.5?
BME (Keith) is coming out with a 55 XTreme engine that would help lighten the total load. The engine is only supposed to weigh a tad over 2 pounds and have all the power of the 60cc engines that that are available and the power of SOME of the 70cc engines. Keith says it should be turning 24" props near 7K rpm.
The engine should come out in April. I have two on order.