I have searched this to death and have came up with no answers. Here goes I just got a low hour 06 yz450f. It has a PC TI4. The jetting is stock as far as i know. The power is great in the mid to upper but low end is lacking alot. I just got off a crf250r and switched to the yami. I swear the little crf had more lowend than this thing. The power is nice and linear but there is just no hit. Seatbouncing doubles out of tight corners is almost impossible. So how do i get some low end out of this thing? Is it a jetting issue? Do i need a new pipe? The bike doesnt bog it just doesnt have that 450 snap that almost every other 450 i have ridden has. I will check the jetting tonight to get the numbers. Also it has stock gearing which seem fine. I had a couple other people ride it and they felt it was lacking a ton of lowend. Like i said before the throttle has no bog it feels good. Please give me some help.