the bike runs bad at low end i put a fmf power core 4 pipe ,128 main jet and the eclip #3 space from the top on the neddle jet and no toil air filter romved the from lid the box.it cuts out at 1/4 throttle it will idle ok for a short time then dies also blowing black smoke .i know its running rich .i have tryed all jetting combos,fuel and air combos . help nothing is working for me . thanks