jetting

[phireboi]

well i have a 400ex thats got everything done in the signature except 406 not 416..but anyway...i have no idea what size jets are in it but before the rebuild we couldnt figure out what was wrong with it and i put in a diff jet(donno what size) to see ifthe jet was clogged and now after the rebuild when i go to wot it just bogs down and will stall out very easy if it loses traction and have to give it more gas what size should i go on main jet?

[EXtremeEXer50]

If i were u i would ask the person who did ur motor work what size jet u need....it sounds like u need a bigger one.

[phireboi]

i found out i had a 170 main in there i went lower on it to a 160 which is all i had and it got worse and put the 170 main back in and cleaned the carb out real well and it was a tad better still bogs from like low rpms if i go WOT. if i ease it into wot its fine but cant even do wheelies now :( what should i do?

[phireboi]

bump pls help

[cals400ex]

so are you running keihin jets or dynojets?

[phireboi]

keihein

[cals400ex]

is the air box lid on or off? is it the stock needle? what compression 406? stock or aftermarket cam?

[phireboi]

stock compression, stock cam, no air box lid, stock needle.

[cals400ex]

so basically with the pipe, piston and no air box lid i would try around a 158 keihin mainjet.

[phireboi]

i tried going to a 160 from the 170 and it only got worse the 170 has worked the best and its the biggest one i got so it leads me to think that i need a bigger one but i dont know how much bigger to go..

[cals400ex]

i would clean the carb, run a fuel filter, and make sure the fuel line is clean. cleaning the carb may help the most. take out all of the jets and spray them with carb cleaner. i really don't think you need a 170. i didn't even run that on my built motor.