I'm swinging a 78" prop, 38 pitch (I think) on the RANS, thanks to the Rotax's gearbox, which I guess is why it's there, as a torque multiplier. I'd...
Sounds obvious as heck, but check to make sure the brakes are not actuated/on, while sitting there with engine running! I still find myself doing so...
My white UHMW plastic Datum skis have worn very well, (hangared) it took a Idaho rock with a sharp projection on it (that would have damaged anything...