Carb re jet problem

[The 400ex kid]

Ok here's my problem I have an 03 400 ex .......well my problem is I have a red graydon pro line exhaust and I was wondering if any body knows the jet sizes and and adjustments for 1900 feet above see level ...... I would be extremely appreciative for any info thanks

[CJM]

42 pilot, 150 main.

[The 400ex kid]

42 pilot, 150 main.

What about mixture screw and needle position

[CJM]

What about mixture screw and needle position

sorry...

3rd clip and 2.5 turns out fuel screw.

[450rtt]

before we can recommend jets it would be wise to know if you are running with the airbox lid on or off. That is a key factor in jetting along with exhaust.

[CJM]

before we can recommend jets it would be wise to know if you are running with the airbox lid on or off. That is a key factor in jetting along with exhaust.

This thread is 2 months old....

kthxbai

[450rtt]

if somebody reads this 5 months or 5 years from now and takes those recommendations to heart i would hope they would have the knowledge to know whether or not a lid was present, it makes a difference in jetting, a substantial one at that and i think the question should have been asked before throwing jetting specs out there. Airbox lid and exhaust are the 2 main things that will effect jetting.

[CJM]

if somebody reads this 5 months from now and takes those recommendations to heart i would hope they would have the knowledge to know whether or not a lid was present, it makes a difference in jetting, a substantial one at that. just trying to help.

right......you just HAPPENED to find a post 2 months old somehow...just like magic and Im the only other poster in it. Stop trying to start trouble.

[450rtt]

For example if i was running an exhaust with the lid off i would be closer to a 165 main jet, with a 40 pilot, and 2.5 turns out, 3rd clip on the needle. That's just my 2 cents. It is very important to know if the lid is on or off in order to give proper jetting recommendations. Really not beneficial to throw a number out there without information like this.

[KKiowaTJ]

Stock they need changed to a 150 main and a 40 pilot. But as it is, Most 400's are one in the same and usually the only factor is the main jet and a/f screw. More so if the person didn't have a box lid, He would have mentioned it. But for the most part, And you can do a search, 150-160 main and a 42p is the most common jetting set up regardless unless a built motor. After that its fine tuning with the clip and a/f screw.