Gurtner carbs having the brass on brass float valves are sensitive to even the smallest spec of dirt making the carb weep or flood. SHA has nice viton tipped float needles so they are more forgiving towards smaller specs of crud in the fuel.
Sha carbs will go right on the cable without changing the molded knarp, usually even without repositioning the cable at the grip if you go for a 14:12 replacement carb for either the D10G or D12G Gurtner (or a 14:14 if you have the GA14 Gurtner stock).