Dave, O.S. FS-70 Ultimate 4 Stroke with pump.....WITH PUMP!!! Now there is a 3D powerplant if I ever saw one. 2000/13000 RPM. 1.2 BHP @ 11,000 17.7 oz. W/muff. Spins a 13/6 prop. A 14/4 would make it a stump puller. Toss this in a 5 to 6 pounder and never turn back. It would make the UCD .46 dance. WITH PUMP !!!! I can see it now, fuel cell on the CG. Whats a US 60 ?
Mark, your almost there with this engine, what about the Twist 3D? Joe