The 26 has the the regulator side of the carb facing the wind blast which is higher in flight than on the ground. The reference hole in the little cover needs to have a tube soldered in, a short piece of tygon put on and inserted into the fuse where the pressures SHOULD remain constant. The way it is stock, as the airspeed picks up the reference hole picks up increased pressure which presses down on the diaphragm holding the needle open more than normal resulting in a rich mixture when you throttle back. It may take a little experimenting to find a spot where the pressures remain constant and don't influence the carb mixture. You can search for pics of the mod here on RCU, that's how I found out how to do mine and it really helped. Good luck.