Hello,

My friend has a 2001 400ex with a White Bros E-series pipe and header. He is running a Uni filter and some holes cut in the air box lid, other than that it is stock. We are at roughly 1100 ft above sea level.. He has been toying with jets.

What jest does anyone recommend?

Thanks

 

We really can't reccomend a jet... because every bike is different. After you put in a jet, run the bike with the air filter off... then run it with duck-tape where 1/3 of the filter is covered... if your bike runs BETTER with either of these- you need to adjust. If it runs better with the filter off- you are running too lean and need a smaller jet... and vise-versa the other way. My 400ex runs a 165 main jet... my buddies 400ex runs a 145- we have very similar setups.

Hope that helps

 

wow, i have never heard of that method sounds sweet. does it work well?
thanks

 

I got that jetting test from calling K&N customer support. I asked them if I could read the spark plug... and there answer was NO- there are too many additives in the fuel that make reading the plug too hard. So he offered me this filter removal/taping technique.

 

Do you still have the number for K&N???

 

yea-

1-800-992-4993 This number is for Dynojet

(702)399-1423. this is for K&N

Both are the same (i think)

You can buy individual jets if you loose them or break them.