2001 400ex.white bros.ehaust and k&n filter. what is a good jetting for this ? thanks

 

well its just not that easy... what altitude are you at? and what jet is factory in the machine? call a honda dealer and find out and then i can help you figure it out..

 

hey thanks for reply.honda dealers wont tell u crap...same ol story bring it in.... as far as altitude highest thing round here is cornstocks. im in cental illinois. thanks for your time

 

it says ill. is about 600 elev. so do me a favor and call your dealer and ask what is the stock jet they have on a stock 400ex..make them look it up for you.. then let me know and we can go from there..

 

hey buddy they are telling me 38 slow jet and 140 main. the guy gave me the stock exhaust when i bought ,,but i hate to waste that white bros. exhaust. hey thanks again for your input. much appreciated

 

by going with what they say is stock, and before you switch these check the numbers to see what is in the quad when you take them out, because i may be set up already.. but is is safe to say you can go up one or two sizes on the main jet it just depends on how it runs after you put it in. the pilot or low jet you can go up one if you choose to try but if it runs boggy off the bottom i would change it back..let me know how it goes...