I'm pretty new to gas planes - former glider guy - and bought an Evolution .61 primarily because I don't want to mess with engines - I just want to go fly. Well, I'm stuck messing with the engine anyway. Right now it has the following symptom: if I idle for a few seconds and hit the gas to 1/2 throttle, it revs high, then drops a few hundred RPM. Kind of brpbrpbrpbrpbrp-BRRRRRRRR-BRRRRRRRRRRRRRRRRR if you get my drift. If I let it idle more than about 10 seconds, I never get to BRRRR - it starts to rev, then dies.

My limited experience tells me it's too rich on the low end. But it's all the way lean - at least as far as the needle valve limiters will allow. Should I just bag these limiters? Or is my diagnosis off, and should I look elsewhere? I found a thread that said these engines often have thread cuttings stuck in the needle valve area, which can cause this symptom - and sure enough I found and removed a bunch. But it didn't help. Any suggestions?