I have an after market muffler fitted to an otherwise standard 08 YZ450F. The bike seems to run very good. The jetting has been richened to a 168 main jet and needle 1 clip position richer from standard. Pilot jet is standard. Ive found the optimum setting of the fuel screw to be 2 1/2 turns out. Does this mean I should go 1 size bigger on the pilot jet and re-tune the fuel screw? My main question is if I have the 45 size (standard) pilot jet fitted and tune the fuel screw to where it runs best as explained above, then fit a bigger (48) size pilot jet and re-tune the fuel screw will there be any difference to the overall tune of the engine?