Im stumped..

[ridehonda400ex]

My 400ex which has the mods listed below has me stumped. Well to start off, it runs great but the A/F screw has me all confused because i got the HMF pipe and put in a 152 main jet and stock pilot, it worked perfect but my A/F crew is all the way in and was all the way in before i got the pipe and when i screw it out even 1/2 a turn gas will come out the overflow. I have it idling when i do this. I have a slight pop on decceleration but its nothing major just like one or two pops. Somebody wanna tell me why the screw is doing this? Thanks.

[RATPACK Z400]

Most likely you need pilot jet if A/f screw does,t work and is all the way in ,that to me says it cant take more air in without more fuel that being pilot too small IMO. But I could be wrong check on here on jetting EX400 theres a section that tells you what you can do!

[sneaky11]

Are you sure u're on the good screw? (Maybe u're on the overflow screw!!):huh

[ridehonda400ex]

Originally posted by RATPACK Z400
Most likely you need pilot jet if A/f screw does,t work and is all the way in ,that to me says it cant take more air in without more fuel that being pilot too small IMO. But I could be wrong check on here on jetting EX400 theres a section that tells you what you can do!


can you rephrase this? i think you may have left something out lol

[RATPACK Z400]

The A/F screw lets more air in with fuel if screw is all the way in you are at lowest setting (least amount)and still not working so higher pilot lets more fuel in to mix with the more air the screw produces when turned out. If im not mistaken .Or it could be backwards !

[ridehonda400ex]

Originally posted by RATPACK Z400
The A/F screw lets more air in with fuel if screw is all the way in you are at lowest setting (least amount)and still not working so higher pilot lets more fuel in to mix with the more air the screw produces when turned out. If im not mistaken .Or it could be backwards !


Im pretty sure that the screw is to add more fuel to the mix. I might be wrong but i think im right.

[nyates450]

If your getting fuel out of the overflow when you turn the screw then you are not on the fuel screw, your on the bowl drain.

The fuel screw is on the carb right next to the intake boot, hidden by the fuel bowl. It is a small flat head. Almost cannot be seen from the side of the bike.

[ridehonda400ex]

heyy ounds like im turning the wrong screw lol. i can see the screw that im turning plain as day. is the bowl drain screw also a flat head?

[sixer3]

Originally posted by ridehonda400ex
heyy ounds like im turning the wrong screw lol. i can see the screw that im turning plain as day. is the bowl drain screw also a flat head?

yes it is.

the air/fuel screw is visible when looking at the bottom of the carb