Another Jetting Question?

[Olla]

How's it going guys? Not bad here. I was just wondering if I should change my jets or not I have a 400 EX. I put a K&N Filter w/Pre-Charger and I took out my baffle/spark arrestor on my exhaust everything else is stock. Any help would be appreciated. Thanks!

[UglyMotha™]

you more than likely do but only you know for sure, what are your symptoms look at your plug does it look on the lean side do you have miss at wot stuff like that and it never hurts to go up a jet size just to see what happen that's the only way you can make it perfect is to try both sides cause you never know until you try it but more than likely you have to rejet cause anytime you increase air flow you need to increase fuel flow also get my drift

[tprender]

You will find that the 400 comes jetted lean from the factory. Most people put in a 40 or 42 pilot to help with stating problems. This will nake it alot easier to start when it is cold. The main to start with try a 152. This is a good starting point. You might find that it will need a 150 or 155. But the 152 is just a good guess.