I forgot to mention that I did drill out the baffle to a #20 sized drill and used copper colored high temp RTV to seal the muffler. The baffle helps with noise and tank pressure.

How long has the engine been running?? Mine had problems until I passed the one galon mark. I am now at 1 1/2 1 3/4 gallons and the power is up and the needle settings are staying put. There have been others that have the rich mid range you have and some don't, I would like to mic the carbs to see if it is a QA or a design problem

Dru.

P.S. Flying helicopters tought me that if I save $2.00 on a plug it could cost me $200.00 to rebuild my bird.