what elevation are you at? do you need the choke to start it? there is an air idle screw which should adjust the amount of air at idle and low rpm. turning the screw in will reduce the air and loosening it will raise it. try turning it half a turn to the left at a time and see how things are, you should notice your idle jump a bit. dont adjust it too much. if you still have the problem put it back to your orig setting and then you will probobly have to rejet. The only other thing you can adjust without changing jets is the needle. if you pull the top of your carb off and raise the clip a position (dropping the jet down) you will reduce the fuel off the start but i dont think thats your problem, unless it fouls while riding wide open as well.
