Thanks for the tips. I fixed the idling problem. Now, I'm left with an engine that dies or struggles at about half throttle. All of the internal parts checked out to be fine. I did have to tighten the muffler and put some thread locker on it; I think that was part of the problem. I had it out flying yesterday and didn't realize that the muffler was loose until it was in the air. It flew almost perfect until the muffler popped out of the cowl, then it shut off. That tells me that it was running to rich. However, when I leaned out the mixture and tightened the muffler, I couldn't get it past half throttle before it stalled. I've had this problem in the past, but I cannot remember what exactly I did to correct it.