RE: another darn ryobi post (ryobi performance modification, analysis and comparison)
My brother has a Ryobi with the slots. It has a slightly larger than stock carb, and the original muffler gutted and provided with a larger outlet, and electronic ignition. No other mods. It turns an 18 x 6 prop at a little over 7500 rpms and flies his 14 lb. +/- 80" span Ryan's Rebel quite well.
AV8TOR