440ex... please help me with my CARB

Ok my engine is being built as we speak.

MODS: 440kit(from magic racing) -- WB E-series promeg slip on --K&N power kit -- XR cam

I ride mostly in wheater that's between 45 and 80 degrees.

I also ride occasionally in the winter between 20-40 degrees BUT I use my stock silencer and air filter.


I would like to jet my 400ex only once and leave it at that...

I would like to know what MAIN, NEEDLE AND PILOT, you guyz recommend for somebody with my mods. AND I NEED HELP WITH PROCEDURE CUX I HAVE NEVER JETTED A MACHINE.




Now the carb on my 400ex is off and I attached a pic of it. I also have my jet kit that came with the K&N powerkit but dunno if I should be using it or buy jets from Honda or whatever...

I really need help as I want my 440ex to run great so I can kick some serious ***.

here is a pic of my carb and I will put the et kit in another post.

Ok and thats a pic of my jet kit:



Also I read another thread about removing the choke and I think that I'm gonna go with that.

Any help or suggestion is appreciated, I also know nothing about carbs so I need explenation on what a main and a pilot is.....

thank you

[400exJOE]

Fallow the instructions in the kit. They will tell you how to adjust the air mixtrue scew instead of replacing the pilot jet. I would put in the largest jet in the kit which is a 170. I have a very similar set up except no cam and I run a 165 main jet. I personally would not remove the choke but you can if you want a little more power. If you remove the airbox lid or anything to give you more air, you might want to purchase a 172 and a 175 mainjet from your dealer just in case.

id say ur jettin will be close to this,

pilot = 42 45 for easy starts

needle = up 1 or 2 notchs to rich it up

main = anywar from 160-170, or mabe higher.

thanks for the help.


The biggest jet in my kit is a 170 and I think I'm gonna use that.


They gave me a needle in my kit..... should I use that one ???????

And can I go to honda and order a 45 pilot ??????



About the choke here is what I was thinking.....

During the summer time I could run without choke, and use the K&N filter.

During winter I could put the stock filter back on, put the choke back on, and put the oem slip on back on.

what do you think of this idea ????


Also I dont want any holes in my airbox lid cuz I do some deep water crossing occasionally and I ride muddy trails as well....

If this helps, this is the list of all the **** that came with the kit.

now what do I do ?????

It looks like 2 jets on top of each other..... I dont get it ????

[400exJOE]

the top thing is the jet. Thats all that comes out. Dyno jet has the phone number on the kit and they are real helpful w/ any questions. i would put their needle in too. I did.

Wich one is the main jet and wich one is the pilot jet ?????

Also I cant seem to find a way to get the needle off ??????? I took the top cover off but dont know what to do afterwards ?????

[PsychoDave]

Go buy a CLYMER book!!!!

I just bought a OEM honda service manual for the 400ex today. Tha **** helps a lot :D

I'm about done now but I still gotta go buy a pilot 45 or 45....




BTW: some thing I noticed. I intsalled the needle that I got with the kit. IT IS SHOTER THAN THE STOCK ONE. meaning iof I out the clip in both if them and the same spot the afterm,arket needle will anlways be 1 grove richer. so I put it on like stock.... Just so that basically I am 1 groove richer than stock.

[400exJOE]

Why wouldn't you want a 45 pilot jet? Wouldn't it start even better than a 42? I just put my 440 in and its hard to start so I would like to get a bigger pilot jet. But what size? I ride in the same temps as the first guy.