the prop in the pic is a dynathrust 16x8.i was getting around 73-7500 the last time i tested it i think.ive switched igns since then to the one with an advance on it but havent tried it yet to tach and see if theres any difference.the other item i need to change is the carb,its the zama 8-9mm.i need to switch to a 10mm but just havent done it yet either.the last time i flew this engine with the older ign it was on a GP G202 1/4 scale arf.it flew it ok like a spiort plane but no vertical really.it weighed 11.25 lbs RTF dry.i purchased a started 28cc stihl and worked on it instead.pic attached so you can get another look at a converted engine for ideas but its basiclly the same as my echo.