jetting the 400ex carb

[Chet]

Well I got my jets for my 07 400ex I am going to install them later tonight, what steps are the easiest, do I need to remove the carb, does any of the plastic have to come off from the front fender assembly, rather than I try different steps, I figured there are alot of guys that doing this on a 400ex was not their first rodeo.
going to install a #42 pilot and a #152MJ

Chet

[jt53142]

I used to be able to to loosen the carb and twist it to change the main jet. I can't remember if you can get to the pilot jet though. Might have to take the bottom bowl off.

[ti2ibal1]

It's easiest to remove everything and pull the carb off. I do it that way just so I have a reason to get out of the house and have a few beers in the garage. LOL

Seriously, it's not hard at all to get down to the carb. I could do it blind folded I've done it so many times. I know you can get at the main without removal, but I don't think you can get at the pilot.

Just take your time and remember where stuff goes. It's a good way to learn more about your new bike!

[ti2ibal1]

One more thing, something I always do to all my carbs is replace the phillips float bowl screws with little cap screws. The phillips ones can get rounded out over time, making the cap screws a better choice.

IIRC, they are 4x14.

[Chet]

where is the plug located so I can remove it to get at the air screw

Chet

[ti2ibal1]

There is no plug over the pilot screw. Being that you have the newer style carb, it's got a D shaped head on it. I can't for the life of me understand why they replaced the slotted design.

[Chet]

Well I got this reply after I thought the plug right next to the part with the d shaped screw, I drilled that plug and after drilling deeper I figured I was doing a NO NO, well it is a special shaped plug with a turned down diameter that goes around a bunch of tiny holes, luckily I am a machinist, I took out what was left of the plug and machined a new one and press it in, I cleaned the area where the tiny holes were with a vacuum cleaner and will try it tomorrow, just got it done around midnight, so never drill that plug. I was thinking of removing the air screw and slotting it, has anyone done that. I take it there is a special wrench from Honda for adjusting the air screw. I hope it runs.

Chet

[ti2ibal1]

It should be fine as long as you're got the hole you drilled plugged. Worst comes to worst, I think I've got an extra float bowl laying around. Let me know.

I don't know what kinda tool you need in order to adjust the pilot screw. I took my stock carb off and installed one off of an 04. I like simplicity. ;-)

BTW, I replied to your PM.

Mike

[Chet]

Thanks Mike

I don't think I will have a float issue, the plug is just between the float bowl and the tower where the air screw is, but you mentioned you changed the carb to an 04, was the also a 38mm, was it a better choice, any improvements, just in case I have issues with this carb, I may have to look around for another one.

Chet

still too early to go out and start it up and see if it will be ok. have my fingers crossed.

[ti2ibal1]

Originally posted by Chet
Thanks Mike

I don't think I will have a float issue, the plug is just between the float bowl and the tower where the air screw is, but you mentioned you changed the carb to an 04, was the also a 38mm, was it a better choice, any improvements, just in case I have issues with this carb, I may have to look around for another one.

Chet

still too early to go out and start it up and see if it will be ok. have my fingers crossed.

Chet,

Both carbs are 38mm. I bought a spare one last year just to have, but ended up using it full time.

Mike