I was wondering if anyone could walk me through how to jet a 300ex that has a Dg full exhaust?
any help would be appreciated!

 

Your best bet, is to find someone you ride with, or in your atv club, whos done this before. Nothing beats a person on the scene , whos done it before.
The best place to start is reading up on the function and different circuits of the carb, and the symptoms of rich and lean. Jetting is basicly getting the mixture to the correct ratio, after modifing a motor.
Increaseing the air flow, with filters and/or pipes, makes the motor run leaner than it should...and jetting restores the ratio back to normal.
Heres a good article on jetting, and if you still have questions...keep asking. If youre handy with a wrench, and can do the simple things like oil changes and valve adjustments...jetting shouldnt be tough.
jetting