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novak8
08-19-2009, 11:30 AM
i just bought a 2000 400ex with a 416 kit. it has a k&n intake and a FMF power core 4 slip-on. it is running to rich and keeps fouling the plugs. i have yet to find the right adjustment on the carb for the air/fuel mixture. any help would be appreciated.
storms400ex
08-19-2009, 12:31 PM
what size main jet and pilot jet do you have??
novak8
08-19-2009, 12:37 PM
Im not sure, like i said, i just got it, and i havnt gone too deep into the carb or motor. but i do know that there has to be an adjustment for the fuel mixture somewhere on the carb but im not sure where or how to get to it
aDviSol2y
08-19-2009, 01:10 PM
before you start messing with the air/fuel mixture, check the size of your jets! If you are fouling plugs, its mst likely your jets!
Kacker05EX
08-19-2009, 05:18 PM
I have an 05 EX and i just bought a FMF Powercore 4 slip on and FMF recommends trying a 150-152 main jet and a 40 pilot, everything else stock....problem is i'm havin a real ******* of a time finding jets in canada...weird
novak8
08-19-2009, 08:15 PM
do you know what the stock jets are in the carb?. the carb thats on it right now is a keihin idk if that makes any difference?
storms400ex
08-20-2009, 06:51 AM
my 05 had a 148 main and 38 pilot stock, should be the same
novak8
08-20-2009, 11:47 AM
how do i check to see what size the jets are? i have the carb off right now but idk how to tell.
honda400ex2003
08-20-2009, 12:28 PM
the jets say what size they are on the sides of them. it should be on the shaft part with a number like 148 on it or something for the mains and the pilot is on the round outer edge with a 38 or something on it. you will have to take the bowl off the bottom of the carb and the pilot out of the cylinderical hole to see what taht is. the main you should be able to read by spinning it around and looking at the flats on the sides of the jet. steve
novak8
08-24-2009, 05:34 PM
im running a main jet (says 175rd on the side) and a 38 pilot jet...it might just be me or is something severely out of whack?

it has been running rich but i thought the guy before me just had it adjusted wrong..
honda400ex2003
08-24-2009, 06:17 PM
sounds pretty close but it may be a bit rich depending on elev. you could go down to a 170 and see how it goes for you. check and see where the needle is too and how the fuel/air screw is and where it is at. steve
novak8
08-24-2009, 07:48 PM
i've already tried checking the needle but i cant figure out how to get it out..this carb is so much different than the one off my bike...