ORIGINAL: desertdog
Thanks to all for the input. This is my first gasser, I want to put it on the giant super sportster. I just got a email from wacker engines and said most of the MTD engines turn a 18x8 at 7500 rpm. So you are probably right, 14000 just is not possible. I will put the prop on the engine this time and try again. I got the thrust reading from a website. Have a great day.
The Ryobi I'm working up now was my first gasser too and it's been flying a GP Giant Super Sportster since spring a year ago (see my avitar). I had done some mods on the motor before I put it in the GSS. It was then pulling about 11.5 lbs thrust on an APC 18x8W. Since then I've done some more work on the motor, the results of which are in this thread, and now I'm up to about 15 lbs thrust. I've yet to put it back in the plane but I think I'll be pleased with the result. The airframe all up ready to fly is 14.5 lbs, not a light weight for sure, but now with a 1:1 thrust to weight ratio it should be pretty good! No unlimited vertical but sporty I suppose!
diceco