mountain riding

[yZaSsAsSiN]

im going to go and ride in the mountains. i have a yz125 and i have a fmf fatty gold series. will i need to buy a new pipe just for the mountains so it will run good???

[250EXking]

ummmm not the pipe, maybe jetting wise. i know my boss took their motorcycle through the mt.s and the higher they got the more the bike seem to wrong worse beacsue of the air differnece. jetting would be your problem.