Hi Dean,

Your problem to me sounds like an air leak, either at the carb "O" ring, backplate or pin hole in the fuel line. If it is a pin hole in the fuel line, or an air leak in the fuel delivery system, you will see air bubbles in the fuel line when the nose is up at full throttle. When you put the nose up, the fuel draw is much greater by the carb and you can see if it is drawing air into the line - if so you know the problem is in the tank or fuel line.

If the carb, or backplate is leaking, you can find it when the engine is at full throttle by spraying WD-40 around the base of the carb or backplate, if the RPM changes - that is where the leak is.

I noticed previously you had a problem with your fuel filter, do you think you might have a partial fuel blockage in the needle valve area from the old filter? Just a thought.

Also, I only use 15% nitro with my GMS - I'm not sure if that will make any difference.

Thanks for keeping us up to date, wish we were closer, I'd like to give you a hand and see if we could get to the bottom of the problem.

Fly4Fun,

Wayne