hi all, need some info on rpm s on the dl, i have one on a Q Q yak 85", after a gal at 2500 rpm, and alot of tunning, i could only get 6000 rpm, on a 22x8 tbm prop, did all i know on the mix screws to get more, after reading some threads and seeing people getting much more thought it might be the engine, so i bolted on my spare, after break in, same numbers,
i built racing engines for gokarts for years and know alot about carbs so i went to work , was able to pick up the engines (both of them) 300 rpm s, just by a few little tricks here and there but im still not getting the 6700 to 7400 that some claim to get on here, but the throtle response was improve a ton.
these are my first gas engine in the rc planes, had always run apc props on the glow engines, is the vess prop where that much rpm is gained?
thanks for any info you might have

xracer