What rpm range is it running bad?
Are you running the airbox lid or snorkle? Either remove or install one or the other and see if it runs better, this will tell you if its rich or lean.
Dynojet sizes are not the same as mikuni. The dynojet numbers are bigger then mikuni. Might want to try a larger main.
white 04 yfz 450-
Venom 98mm 14:1 piston, Venom porting, Venom pipe, Venom RAT, 42mm fcr (by sredrum), ESR intake and more...
02 grizzly
27" tires, white bros slip on, winch, kodiak clutch weights,
reverse rev limiter override