Main Jet

[crazy4atvs]

I just bought a new HMF slip on for my 05 400ex. It came with the main jet, Can anyone tell me how to install this jet. Is it simple or hard.

[coryatver]

-turn the gas off

-start it up and wait for it to stall out

-there is a 18 mm cover on the bottom of the carb take that off

-the main jet is up in there take i think it is a 7 mm socket and take the old one out

-put in the new main jet

- put cap back on

-turn gas on

-roost away!

It only takes like 5 minutes.

[crazy4atvs]

thanks a bunch, One more question do I have to take the carb off?

[underpowered]

taking off the carb will make it easier, but not required.

BTW, the plug on the bottom of the carb is 18mm, the MJ is a 6 or 7mm,

you may have to loosen up the clamps and turn the carb slightly.

[2004exrider]

17mm and 6mm, just got done messin with mine.

[JOEX]

Originally posted by 2004exrider
17mm and 6mm, just got done messin with mine.
Yep, it should be a 17mm for the bowl cap and 6mm for the jet itself. The newer years could be different though.

Simple to do, no need to remove the carb. It's difficult to actually see the jet, just feel around for it with the socket. A 1/4" drive socket and a short extention is good for this. Be careful not to cross thread or over tighten the jet when installing.