Good advice from avi8tor.

I'll add that among my several gas planes, I've one that goes richer inverted. I suspect the cause is gravity influence on the atmospheric diaphragm. It is a rear carb 35cc and the diaphragm is on the bottom of the carb when upright. I suspect that the little spring is slightly weak and that when inverted, the weight of the diaphragm opens the float needle slightly more. If/when it gets rebuilt, I'll substitute a slightly stronger spring and see what happens.