Just wanted to say thanks to everyone who has posted here. This has been very informative to me because I am new to this hobby. I also own a Tower .46 and just received my GMS .47 today. Brand new in the box for less than $50 on ebay. I had the same probs with my Tower engine and got so frustrated that I sent it back. I installed my GMS on my Hanger9 trainer and ran three full tanks through it. I then filled it up again and adjusted the high speed a little and leaned the LS about 1/8 of a turn and put her in the air. It ran so good I couldn't believe it! Thanks again everybody!