need jet kit help....quick

[garysol1]

I am doing a jet kit on my 400ex. someone has been in it before me apparantly. My question is about the emolsion tube. Mine was threaded into the carb body and has a lock nut with about 2 threads showing below the lock nut? Is this the stock arrangement? I called dynojet and they could not tell me anything about it. Please help.....I need some input. Should I install the emolsion tube until it bottoms out or leave it at 2 or so threads showing. Thanks so much

[cals400ex]

what is the emulsion tube?? from how it sounds your talking about the needle jet holder. the needle jet holder is the piece that the main skrews into. is this what your talking about?? if it is, you should see about 3 to 3.5 threads after the nut is tightened down. if you turn it in farther your mainjet will actually not be as low in the carb when you turn it over and won't be getting fuel as easy. this will hurt your performance as much as an improperly adjusted throttle cable. let me know if you have any other questions.


check this thread out. there is a nice pic of a 400ex carb:

http://www.exriders.com/vbb/showthread.php?threadid=64555&highlight=needle

[Doibugu2]

or this might help.

http://www.exriders.com/vbb/showthread.php?s=&threadid=19832

[garysol1]

THANK YOU THANK YOU........:)

[cals400ex]

Originally posted by garysol1
THANK YOU THANK YOU........:)


no problem, let us know how it goes

[garysol1]

I have jetted probably a half dozen bikes and quads and I have never had a bike as picky as this. I installed and reinstalled the kit 3 times to get it to run. Maybe it was a just fowled plug all along:) Thanks for all the help guys.

[cals400ex]

i assume you know the jets in a jet kit are not numbered the same as keihin jets. so, a 150 keihin jet is NOT the same as a 150 dynojet. also, the keihin needles and the dynojet needle has a different taper to it. so, the clip position may differ with each needle too. however, i think you have the option of using a washer under your needle with the jet kit and this washer did not come on the bike from the factory.

[garysol1]

Originally posted by cals400ex
i assume you know the jets in a jet kit are not numbered the same as keihin jets. so, a 150 keihin jet is NOT the same as a 150 dynojet. also, the keihin needles and the dynojet needle has a different taper to it. so, the clip position may differ with each needle too. however, i think you have the option of using a washer under your needle with the jet kit and this washer did not come on the bike from the factory.


It looks like I basicaly redid the same jet kit that was already in the bike. Kind of a bummer. I went and did the full install anyway just so I knew what I had.