I have a Brodak 40 that was broken in on the bench per Brodak's instructions and ran great. They state break in w/o muffler. I now have it mounted on a Sig Force, powermaster 10/22, zinger 11x4, plastic tank set up on uniflow, stock muffler. (Have not flown yet do to following problem)
No problem starting, runs rich and then runs away, cannot meter with needle. May take three turns to richen back up and then quits. As the needle is richened....counterclockwise....it seems to lean and then richen and quit.
Reset needle, will hot start with no problem but as soon as you pinch the line or point nose up it runs away.
Tank height about 1/8 above venturi and I have lowered. I have changed to a metal uniflow, a metal standard vent, replaced nva with a kustom kraftsmanship nva, changed plugs from fox std, k&b 1L, os #3 and 8, fireball hot.
Tank has 1/4 foam backing and I have not noticed any foaming in lines. Changed to a Big Art Tongue muffler, fuel line has been replaced, prop is balanced.
The fuel runs great in a reworked OS 40 FP that I am flying in an original TF Tutor , running uniflow tank...... It runs a 4-2-4 break and never misses through the complete tank.......
All of these changes and same result.
What am I missing with the Brodak set up? Help!
Alan