I have been trying to get my 99 to run better, First it was rich, dirty plugs.But went like a rocket while running A new needle jet and nearly seized it up!. back to the old jet and a 31/2 slide to replace the 3 ,spit backs on pick up but sooty plugs on the move. back to the new jet and raise the needle,better running but still spits back. Then looking at the new jet its marked T , with no air bleeds,thanks carb experts! drill the air bleeds , ,,worse, T may mean two stroke?, different internal shape?. Back to old jet and a 3 slide. ,wonder what it will do tomorrow?.