Originally Posted by
speedracerntrixie
IMO if you were to run any of these reed inducted gas engines past 9,000 rpm you will have failures pretty quickly.
I agree completely with the above. These engines all have cantilever crankshafts (supported only in the front) with a single counterweight and are simply not intended for high RPM operation. Add to that the reeds may not be designed for high speed operation and may fracture or otherwise fail. If prop length is an issue, get a taller LG or run 3 or 4 blade props to properly load the engine. If you need / want high RPM operation, get a Zenoah or something similar with a crankshaft designed for that.