Heres the run numbers with 9 inch props and Davis Plane fuel for plain bushed engines I did bump with my electric starter simple primed the engine tuned out the compression screw and slowly turned it it as I cranked till it fired this saved a lot of time and ran wood rev up 9x5 9990
MAS black plastic props 9x5 11800 MAS black plastic 9x4 a steady 12900 it did hit 13150 but wandered steady at 12900 this was the combat tuned did not have time to do the regular 15 today still only about 25 minutes total run time so may get better the carb needs a little work to smooth up the action not a big thing and the other carbs are quite smooth and it is as loud as glow engine and will need the exhaust ring to quiet it down
the PAWs exhaust rings are on the way for all engines martin