this is gonna sound like a newb question:

i just got the white bros E-series pipe and i need to rejet. the pipe didn't come with jetting specs tho. i was told to increase the main to a 127. what does this mean? i don't know anything about working on carburators, should i just take it to my dealer and have them do it?

 

I don't know that there is a 127. There is a125 and 128though. The 128 is a good starting point on any 300ex with a pipe. You can change your main jet if you can change your oil. Take the carb loose from the engine, take the 4 screws out of the bottum of the carb, remove the"bowl". The main jet is brass colored about an1/8 socket. Remove the jet and put in the other one. If you got that far it will go back together nicely.

 

ok, kool. thanx a lot. but how will i know if i got the right size? i know how the quad runs when it's lean, how will i know if it's running rich? thanx for the info.

 

This site might help you out some with what you are looking for. It will not be exact because it is explained on a 400 but close. On step 20 you will be removing the jet next to the one it is pointing at because this is for changing the pilot jet.

http://www.exriders.com/techarticles/pilotjet.html

 

thanx, i'll check that site out