jetting 400ex

[s23599e]

hi, i buy use 400ex '00
the guy before make it

put a k&n filter , remove spark arestor and put main jet 162

me, i put spark arestor only

the 162 main jet is it too big???

the plug check is ok( good color)

why member of atvrider have

440ex, pipe and filter with jet 158
and me have stock engine, no aftermarket pipe just filter a jet 162?

[Chino886]

I don't understand what the heck you are asking here...:confused:

[sickmojave]

Originally posted by s23599e
hi, i buy use 400ex '00
the guy before make it

put a k&n filter , remove spark arestor and put main jet 162

me, i put spark arestor only

the 162 main jet is it too big???

the plug check is ok( good color)

why member of atvrider have

440ex, pipe and filter with jet 158
and me have stock engine, no aftermarket pipe just filter a jet 162?

ok I think I can translate this

the guy that sold you the quad put in a K&N filter and removed the spark arrester then rejetted it with a #162 jet.

you put the spark arrester back in and want to know if the #162 jet is to big?

you seen on this site that a member is running a 440 with pipe and filter and only a #158 jet ,but you have a stock engine with a 162 jet and it makes you think that you have to big of a jet in your's.

well you are right. you have to be running way to rich. I would try a #152

[s23599e]

thank for translate, scuse me i live i quebec city and just speak french

but, my spark plug color is good

this is best if i put 152 main jet???

[cals400ex]

i would run a 150 if you did not modify the air box lid. however, your elevation and temperature will play a role too. the larger main jet you go, the slower you will be at higher rpms and top speed.