blaster jetting

my brother has a blaster with an lrd exhaust k&n filter air box lid off, and my cousin has a stock blaster that is faster. i think that the jetting is off, what should the jetting be for sea level (we mostly ride at the oregon coast). also it barley runs where we live at 3200ft or so. it had a 310 main when we ran it against my cousins blaster.


p.s. i never really rode it so i dont know much more.

the plug should be a golden brown color. if its to dark, lean it 1 jet, if its to light, go up a jet size.

i'd start at a 260 jet and work my way from there.