Mac: Suggest you check the overflow return tube which allows excess fuel in the header tank to be drained usually back into the left wing tank. The symptoms you describe would suggest that there may be a blockage in that pipe. Locate the wing tank the return pipe is hooked to, undo the fitting, pour fuel into the header tank until it is completely full, then check to see that the excess is in fact draining back into the appropriate wing tank. Good luck!
Bob Blanchard CD N94676
