If I read you correctly are you saying you have engine run problems when inverted also? While I do agree with Jim in his suggestions I am going to offer an alternative to running problems that is a bit out of the ordinary at least for controlline and flys somewhat in the face of conventional wisdom concerning fuel systems, tanks, uniflow and so forth.

Since you are using a 40 FP I am assuming you are using a muffler with pressure avaliable I think you will find by the simple expediant of useing a bubbless tank from either Jett or Tetra all your uneccessary inverted landings will vanish.

Unlike the somewhat difficult setup to obtain for uniflow and certainly none of the shop time neccessary a bubbless tank on muffler pressure can offer superior fuel delivery characteristics. Even though the tank looks conventional it has no clunk the fuel feeds from the middle of the tank. The tank can deliver from as far aft as the CG if you want. There is no critical height problem and no orientation issues the tank can even be mounted vertically if you wanted And there is no vibration issues at all. It is sop to hard mount them (no foam).

I have an old 40 FP on my Magician that works magnificently with a Tetra four ounce.

I do suggest you fuel them from a large syringe however and not a fuel pump to gain the most benefit however as this assures there is no air in the internal bladder.

John