I recently purchased a slightly used Extra 300XS with an OS 1.60 on it. It's running a 18x6 Pro Zinger, Perry oscilating(sp?) pump and a Turbo-Jett in cowl muffler. Now for the issues.. With the pump on it I cannot get the high end lean enough to run very well... In flight it looks like I've got a smoke system on it and it runs very rough. I took the pump out of the mix and readjusted the needles and it sounds great on the ground and runs up well but goes lean after about a minute of flight. It seems without the pump I can't get it rich enough. All the fuel lines are new and the tank is sealed and the internal pick up is all good. The only thing I noticed was an excessive amount of air in the line from the remote needle up to the carb... Do these remote needles have tendency to leak air?? This is my first large glow engine and so far I'm not too happy with it. I know it's an air leak somewhere I just can't find it.

Any suggestions would be great.

Thanks.