what jets for 300ex

[300exryder03]

hey i have a 02 300ex with a white brothers e series pro mag pipe. now when i let loose on the road it seems to back fire. can any one help me on wut size jets to rejet the carb? thanks

[beak7707]

I would take the main up a couple sizes. I used to know what size I was running in mine but it's been gone too long. Free bump anyways maybe somebody else can help you out.

[bulkdriverlp]

what all mods do you have, is that pipe slip-on or what?

[300exryder03]

yes it is a slip on... and i have a uni air filter.

[bulkdriverlp]

turn ur pilot screw out a 1/4 turn at a time keep tryin it i have full system and twin air filter 132 main,needle 1clip down, not sure on the turns of the pilot screw thou

[300exryder03]

i found out that i have a 38 pilot and a 122 main. can any one give me any suggestions. some where i heard that if u have a white bro's pipe that these jets would work. 158 main and 42 pilot??????? thanks

[300exOH]

158 is way too big. The 42 pilot will work but I would try 128-135 main. Pilot screw should be 1 1/2-2 1/2 turns out. If you are at a high altitude (above 3000')you'll have to go larger on the main.

[300exryder03]

ok thanks i will try that out.

also i am getting new front tires. right now there stock 22x7 should i go to a 21 ? thanks

[bulkdriverlp]

the stock main is 122, just go up to maybe 128. move clip down i notch. whichever you wanna do with the tires, its up to you whatever you like better.

[300exryder03]

so 128 will be fine in the winter ?

[300exryder03]

Will a 128 work in the winter round 10 degress F - 30 degrees F?

[jeepeater347]

Are you running with the air box lid on or off?

[300exryder03]

on

[Out_Sider]

if i were you, i would run a 135 main and keep the stock pilot, should run pretty nice, that is what i used atleast and it was good

[hardkoratvmxr]

i put a 128 main jet in and moved the needle one clip position and i have an hmf slip on

[Aceman]

Originally posted by 300exOH
If you are at a high altitude (above 3000')you'll have to go larger on the main.

You mean down on the main, not up. This is the reason some 300ex's come with a 120 main in the higher altitude cities. But I would try a 40 pilot and probably a 128 main to answer your jetting question.

[300exOH]

my mistake sorry.:o