JDW
You are absolutely correct. I adjusted the idle screw to a more lean position and am able to idle for well over a minute and then throttle to full throttle with no problems. I believe I have the needle out appox. 1 1/2 turns out and the main needle is out 3 1/4 turns. It now throttles up great and does not spit and sputter and die! Everyone should try leaning out the idle needle instead of all this filing and drilling out stuff. It is VERY SENSITIVE! You move it 1/8 of a turn and it could kill the engine in either a too lean or too rich setting. I have now ran 30 oz of fuel this evening without incident! Before it always would die in transition and you would have to dead stick the engine. Thanks everyone for all your information and inputs but I will just stick with the adjustments and not modify anything!! They build these this way for a reason. Why modify if you can adjust the problems away?!?!?!? I also confirmed all this information with a Tower Hobbies, where I purchased my engines, Technical Rep. who DOES NOT RECOMMEND filing or drilling ANYTHING. The only problems they have been unable to solve is if you use a Pitts style muffler on anything less than the .61 on the GMS engines.