My 46FX has had about a gallon of fuel ran through it, it has alwasy ran perfect from the moment I got it untill just recently. Now it will run fine on the ground but when I take off the engine will quit with in 2 or 3 mintues of being in the air, no matter what throttle setting. I have checked both needles and they seem to be adjusted right and changed plugs. etc. When the engine does quit it is abrupt, with no apparent signs of being to rich or lean. Anyone have any advice, or a simular problem?