The manual suggests a 24x10 or 22x12. I have one coming that should be here today or tomorrow. All I had was the solo prop which is a little to small for the engine, a 22x10 3 blade is what I've read on RCU is the right size for a 3 blade.

Wild Bill, the carb is the next step although on a new engine I would hope that wouldn't be the issue. I started with the needles set where you suggested but it wouldn't even start until I was 3 turns out on the high speed. I guess that would likely indicate a fuel flow issue in the carb although the cylinders and plugs were wet when I pulled the plugs to check them.

What do you suggest gapping the plugs to? The manual says nothing about plug gap, I found online anywhere from .024" to .038". When it did run they were at .024" and after not being able to get past 4400 rpm I regapped to .031". I put them back to .024" after not being able to get it to start at all, but it still won't. Guess I need to find a carb rebuild kit. Having no gas engine knowledge, do I need to get a kit from zenoah or are they available at a small engine shop? In other words, are they an industry standard carb that is just being used on an RC airplane engine?

Thanks guys.