I just did Dave's Mod to my 99 xrl, and also drilled the muffler. Upped the main jet to 160, and 58 pilot-after trying a 55. Screw is around 2 turns. It runs much better, but I think it needs a 14 tooth front sprocket. I am around 100 feet above sea level. It will now power wheelie 1st, but 2nd is still a no go. My problem has been trying to get the rubber boot from the air cleaner to seat fully on the back of the carb. It is almost like it shrunk 1/4". I can get it to fully seat, but when tightening down the clamp it pulls one side or the other off enough to where you can see it isn't right. I even pulled the carb off the front boot a little, and it still won't get what I think is right. I am about ready to move the whole airbox assembly forward a 1/2". Anyone else had this problem? Any tips?