I recently installed the Factory R&D P-38 Lighting assembly to my 01 YZ426F . I have stock jetting and a Thunder Alley pipe . I was out testing it out today and it seems as if I blip the throttle that it about kills the engine . I have to roll on the throttle slower . wasnt this mod supposed to improve my bottom end . I have no idea if I'm running the right jets . How does a guy know . I dont foul plugs . It rarely pops on deceleration . I know , I Know ( I should have done the BK Mod . Well I already had bought this thing From a Guy on E-Bay . So It should do what it claims right . Please anyone with experience on these things let me know what I am doing wrong . Besides spending $70 on a bolt on piece of junk.