Hi guy's;

I have a Ryobi 26cc and get the following with mod. muffler, stock flywheel, larger carb and enlarged ports.

18x8 ma. 6900 - 7000rpms
18x6 ma. 7440rpms
17x8 apc. 7290rpms
16x8 apc. 7800rpms
16x6 apc. 8000rpms

16x10 zing. 6700rpms
16x8 zing. 7200rpms

I have done two conversions now this one and a Stihl 54cc.
so I am no expert. But both engines do not like zingers. I don't listen to hype about diff. props, I just go by results. I have put a fish scale on the ryobi and all the thrust dropped when using zingers. Down to 9.3lbs with the 16x10.

I now fly the 18x8 ma. on a 14 - 15 lbs clipped wing cub and before I installed the TME. smoke kit, she would hang on the prop for 5 - 8 seconds. Just a tad more hp. and I could hover . I tried other props too but got tired of typing . Hope this helps.

Peter