400ex stalls

[xanadiu]

I recently bought a used 2001 400ex and
noticed it stalls all the time when idling.
I put in a new spark plug but that didn't work.
Is it maybe a carb problem? I am new at the
atv scene.I even tried tinkering with the idle
screw but that didn't work either.anyone with
any ideas will be greatly appreciated,thanks!

["BLAHH"300!!]

your talking about after you ride the bike for a while and let it get warmed up- ??- it still dies when ideling or--
after you first crank it and let it go a minute it won't idle??

HAs the bike been modified in any way....carb,,muffler,,etc. Has the air filter been cleaned lately???

[knighttime]

Put a bigger pilot jet in that mofo. All 400's come lean for enviromental reasons. After you put a big pilot in there, u can tweek it with the small carb screw, or maybe just the black throttle adjust knob on the carb will do the trick.

[RideRed04]

You gotta pull the clutch in, or it wont start. :D Mine doesnt work right untill it is warmed up, so I would check that.

["BLAHH"300!!]

if the bikes in neutral the clutch shouldn't have anything to do with it- i'm sure you know

[xanadiu]

Originally posted by EX-CITING 300
your talking about after you ride the bike for a while and let it get warmed up- ??- it still dies when ideling or--
after you first crank it and let it go a minute it won't idle??

I'm talking about after it's been warmed up
even after 2hours,I have to give it a little gas
or else it stalls... not the easieest thing
to do considering I got 5 hours of riding
under my belt.

[xanadiu]

there hasn't been any modification on this bike.
The guy I bought this from bought it for
ice fishing.He only used it during winter.
The air filter is clean.My buddy has a 400
thinks it's a minor problem...maybe a jet problem or something like that.I don't notice by turning
the idle screw either way it does anything.

["BLAHH"300!!]

POP OFF YOUR CARB AND GIVE IT A GOOD CLEANING-
WITH THE PROPER CARBURATOR CLEANER- AND PUT IT BACK ON- SEE WHAT THAT DOES? MAKE SURE YOU HIT YOUR JETTS GOOD-

[RideRed04]

Being that it was for ice fishing, it was probably rejetted for the cold, making it rich now. I agree with all these hosers on here on the jetting thing.

[4punksdad]

are you SURE you are turning the right idle screw? maybe you are turning the mixture screw?

I doubt an ice fisherman doinked with the jetting..............

make sure your throttle cable has all of the slack adjusted out of it also.

if your not experienced, have your buddy tweak it and see if he can help you out, that way, if he knows what hes doing, you guys could probably fix it. i also go with giving your carb a good cleaning. if worst comes to worst, take it to the shop and theyll probly figure it out.

keep it real:devil

How does it start when cold? Is it really easy to start (i.e., no choke required)?

I'd like to think that the air/fuel mixture screw (located under the carb, right in front of the floatbowl) may be turned out too much. This will cause the quad to run rich in the idle curcuit when warm. To check, get a small screwdriver and turn the screw til it's lightly seated (turned all the way in). As you do this, count how many turns it takes. If it's around 4 turns, then reset it to about 2 1/2 turns out.

Normally, folks have to turn this screw out 1/2 to 1 turns out from the factory, because it's too lean and it's hard to start.

If this isn't the problem, you need to take off the floatbowl and unscrew the pilot jet (it's got a slotted head, it's right in front of the main jet). Check what size is stamped on it. It should be a #38. Next, inspect it and clean it, noting any junk stuck in it.

These are the things I would look at and steps I would take.

Hope this helps,
ogre

[xanadiu]

Thanks you guys for all the suggestions.
I will work on it this weekend and try the above
mentioned.It's good to see the awesome community
of honda owners helping each other.
HAPPY RIDING EVERYONE!!!!:)

[JabberJaw]

I just keep the throttle wide open at all times :-)

[400exJOE]

If you need to keep the gas on to keep it from stalling, it probably needs the idle to be higher. Warm up the quad and turn the idle screw clockwise until it runs w/o you being on the gas.