running rich

[dune cowboy]

need help , my 02 400ex is running a alba slip on , stock header , k&n w-air box lid off, kien 42 pilot , 155 main & the thing is still running rich and popping on decel,, i usualy run at sea level -( glamis ) i cant figure it out need help , where are the air fuel screws ? oh ya also stock needle one postion down ..

[pead_24]

i heard if its poppin on decel its to lean?? :confused:

[mgaskey]

yeah i dont think your too rich, do a plug check to find out.

[plkmonster2]

Hello, and welcome to exriders! I'm sure many people will be able to help. If it is popping when you let off the gas, you are too lean on your pilot. Most likely, your mixture screw isn't screwed out enough. Screw it it until it lightly seats, and then turn it out 2.5 turns. That should fix your problem. If it still pops, try 3 turns out. If the problem persists, your pilot jet could be clogged. The air fuel screw is on the bottom of the carb (mixture screw). It's hard to find the first time becuase it is right infront of the bracket that holds the idle screw. Your main jet sounds right on for the 70-90 degree weather (I think??) Glamis has.

[zephead400ex]

Welcome to the site. plkmonstor2 is right, it is lean if it pops on decel. Like he said, check your main. Your jetting sounds about right on but every machine is different.

[cals400ex]

yep, just start turning the fuel screw out a little bit at a time until it goes away.

[KY Woods Rider]

It depends on what you mean by "popping" on decel. I generally think "popping" means a sharp cracking sound. If so, you're too lean on the slow circuit.

If what you mean is that it makes a deeper toned "poof" sound on decel, you're too rich; although you can get an occassional "poof" even with good jetting.

Either way, the pilot screw is at the front of the carb toward the bottom. The bracket for the idle adjustment screw will be hiding it if you look from the left (shifter) side. It's a small brass colored flathead screw and is pointing straight down.

IN = Lean
OUT = Rich

Go 1/2 turn at a time in which ever direction you need to go. If you have to go more than 3 turns out from fully closed, you need a bigger pilot. If you find the correct setting at less than 1.5 turns out from fully closed, you need a smaller pilot. If you end up somewhere around 2-2.5 turns out from fully closed, your pilot jet is perfect.