Jet mod when in a pinch.

[khen]

I'm not sure if anyone has done this mod before or not so don't shoot me if it's common knowledge.. Anyway, I went out to a few dealers looking for a Keihin pilot jet for my 400EX. It turned out nobody had one in stock but all of them had a more common Keihin jet that was identical except longer.

I was anxious to get my EX back together so I bought one of those and cut it to length and then cut a new screwdriver groove in the top with my grinder cutoff wheel. I put it all back together and it works great!

Nice thing is that this jet is less than half the price of the EX's. You just have to make sure you clean the metal fragments off it real well before installing.

[cals400ex]

what size pilot jet did you get?? just wondering because the 42's and larger are suppose to be longer. the 40's however, will be the same length as stock. just make sure it is a 21 series jet and you will be fine.

[khen]

ummm.. I got a 42 hahaha.. Perhaps I cut it down for no reason?? With it full length it appeared as though you couldn't get the little white plastic baffle plate that slides over the main jet back on correctly. Do you reinstall the baffle or just leave it off?

[hondafox440]

Actually, a 42 is no longer than a 40. The holes in the 42 are just larger, thus allowing more fuel through.

I'm surprised yours worked, lol. I would never trust a jerry-rigged jet in my machine though.

[khen]

Originally posted by hondafox440
Actually, a 42 is no longer than a 40. The holes in the 42 are just larger, thus allowing more fuel through.

I'm surprised yours worked, lol. I would never trust a jerry-rigged jet in my machine though.

Oh it works.. probably better than yours.. in fact probably better than all of yours! LOL. JK :p it's trick :macho

[cals400ex]

my 21 series keihin 42 pilot jet was longer than the stock one. i have read that numerous times on this site too. wait, i will go check right now. i have a 42, 45, and the stock 38 here.

the stock pilot jet is ~ 2.4cm
the 42 pilot is ~ 3.0cm
my 45 is in my bike right now, but i know it was longer than the stock one. i am almost positive it is the same length as the 42.

that baffle plate stays on. with the stock pilot jet, when you skrew it in place, it goes down below the surface of the carb. with these 42 and 45 pilots, it is almost flush with the carb when it is fully seated. the baffle plate only goes on one way. turn it 120 degrees and it will fit on within 3 times of turning it. your cut off pilot will work just fine given that you have a 21 series jet. they make either a 20 or a 22 series also, i can't remember which, but this is not for our bike. i believe the threads are different. i would just make sure you have the 21 series and you will be good to go.

[hondafox440]

Thats weird. I could have sworn the 42 was the same length as the stocker.

[L.Vegas400]

the 42 i just bought was longer than the stocker. i bought it from steve abbot and he says that you cant get the 42 in the same length as a stocker anymore. suposibly the longer ones work better.

[cals400ex]

i find the longer ones a little easier to install and remove. however, its no big deal either way.

[khen]

Originally posted by cals400ex
i find the longer ones a little easier to install and remove. however, its no big deal either way.
Next time I'll save myself the effort and not cut it down :D.

I went riding all day yesterday and the modified one worked well albeit a touch rich. I might go pick up a 40 and try that.