open up the cowling a little with a dremel or some kind or rotary tool where the carb is. but if the engine runs just fine with the cowling on but has trouble getting it primed then just open the throttle, put your starter to the engine and put your finger over the exhaust. this will do the same thing that covering the carb will do. but i would still open the cowling a little around the carb unless there is quite a bit of room anyway cause then it will get more air.