[WildBill]

you could be having a pressure differential while in flight due to the cowl, sometimes if there is too much pressure in the cowl it will affect the diaphram on the carband cause the motor to richen signifigantly, i had it happen on my small edge, we silver soldered a small brass tube over the hole on the carb plate and ran a piece of fuel tube inside the fuse and it solved my problem. or you could be still too rich.