I think you're right about that, Mr. Cox. I heard from another that the engine was quite good as a sport engine, and would turn larger props with ease. Mated up with the right airframe and prop, probably would have been a really nice performer. There are a few bad engines out there. But I think a lot of times modelers might be expecting more out of an engine, not understanding the mechanics of the situation. An engine in a marginal application with the wrong prop will more than spell problems.

Case in point, not long ago I tried a 7x3 prop on an Enya .09-III TV on a sport plane. It flew very .049 like. Someone unfamiliar would conclude the engine was a poor performer. I switched to a Top Flite 7x6 wood, it became a totally different airplane with very good airspeed. Problem with the 7x3 is that I was outside the Enya's power curve. That engine has high torque and maximum horsepower at a lower RPM than the modern Schneurles. Then the engine's heavier weight redeemed itself by its strong running characteristics on a different prop.

I think it may be the issue with the TT GP-18. WIth the right prop might make that engine a really sweet performer on the right airplane.