So my fuel line in the tank does not go up and down. just back and forth. I have it out am holding it up to the light to see what the clunk is doing.
Could the melal tube that gois into the tank be to long to alow the fuel tube to bend. mine is about 1x2 inch long inside? This is a 9 oz tank on a tower trainer .40 motor.
I understand about the motor leaning out in flight.

Thanks Tom