opjose, thanks for the reply.

I actually was just reading about the exaust nipple on another forum, also the exaust joint as well....Mine leaks of course and I get the grey residue on the side of my plane. So this is the next thing I will try next week, Its snowing here today.....blahh. I actually never thought of back pressure being an issue, but it makes good sense.

About the settings of the needles, I can't be positive because it has been awhile since I removed the low limiting collar but I was thinking that the factory setting was over 1 full turn out. So I was worried I may being trying to run the engine lean, can anyuone give me a ballpark figure on the low needle for a starting point. Setting my OS engines is a breeze, but this thing just doesn't respond like an OS. I would have made better notes about the factory settings but I didn't think it would be such a pain to tune.

Can you tell Im a noobie.....lol