Need Some Help With Jetting!

[400exrida06]

I just ordered an fmf titanium 4 for my 400ex and it should be in at the end of the week, my dads kind of pissed at me because im putting alot of the money im supposed to be saving into my 400ex. He says that im going to have to jet it (i already knew that), then he goes on how its gunna cost me alot of money and stuff and i told him we would do it ourselves, but i need some help from someone to walk me through the steps, i think im gunna keep my air lid on because theres alot of dust and mud around here, and im also going to be putting in my uni filter when i get my fmf, thanks alot for all the help, and sorry about posting this question again!

[FoxMxRiders]

buy a couple of kehein jets and you will be in bussiness man ;)

for the rest,open a little your air screw,and put a bigger main jet

[400exrida06]

Originally posted by FoxMxRiders
buy a couple of kehein jets and you will be in bussiness man ;)

for the rest,open a little your air screw,and put a bigger main jet


Where are you located in Canada?

And what size jets do you think i should buy?

[zephead400ex]

42 pilot, 155 main. Check out the FAQ, jetting is easy but can get teadeous if you have to fight the jetting.

[FoxMxRiders]

Originally posted by 400exrida06
Where are you located in Canada?

And what size jets do you think i should buy?
im more at east than you

[omaits]

Just cut a big hole in the middle of your airbox lid (so only the rim is left) and put an outwears airbox cover underneat the lid. I have done this to mine and my airbox stays as clean as when I had hte lid on. I ride through mud and water all the time. If you are going to spend the money on an exhaust, you might as well do the $20 airbox mod as well. Just tell your dad you are a biggy boy capable of making your own financial decisions. :D

[400exrida06]

does anybody run a 42 pilot, 155 main with there fmf t4? I just have no clue on what jets to buy because im knew to this, and how long does it often take to jet a piped quad with a filter?

[cals400ex]

check this out:

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


i would start with a keihin 42 pilot jet and a keihin 155 mainjet. you won't need to mess with the needle like this link shows. also, i would start the fuel screw at 2.5 turns out from lightly seated.