a strip of rubber tire from an old bicycle tube between the boot and the carb works good. Just slide it in and tighten the carby up with the 8mm bolts.
a thicker piece of celophane will work too with a hose clamp around the boot. vaseline the lip of the boot for a better seal if need be.
a thicker piece of celophane will work too with a hose clamp around the boot. vaseline the lip of the boot for a better seal if need be.