still poppin and actin up

[pdanko]

well i was on here before with a problem of poppin through the carb and won't idle, i cleaned the carb ,checked the boot between the jug and carb, new gas, new plug. just put it back together and it is still actin up. got it to idle after i sprayed some carb cleaner around the boot. it was idling fine for bout 10 min but as soon as you hold the gas on any amount off idle, it cuts out and backfires out the back all while occasionally poppin through the carb.... wtf :huh

[CJM]

Whats your jetting?

[pdanko]

its all stock

[JOHNDOE83]

The only way to find out if its jetting related is to run some basic tests.

Turn your a/f screw out and see if it helps at all, try adjusting your needle, dont worry about the main jet. Try to put the choke on halfway and see if that does anything to make it run better, if these things have little to no effect it may be your float position.

If all checks out fine and still runs like chit, you may be missing a part in your carb or may even have a internal motor issue.

The only way to find out is trial and error, testing and re-testing, try to match all your carb parts with a parts diagram...etc.

[pepshocks]

mine does the same thing. . this is the 3rd 400ex that did this popping

[07honda400ex]

you guys have to adjust you a/f screw! and get the stock jets out of the carb they are super lean from the factory! just to pass emissions! even if your bike is completely stock up your main some a 148 is just to lean! any kind of popping is a lean sign!

[pepshocks]

I'm bone stock, what should I bump up to? Pilot jet also?

[CJM]

42 pilot, 1.5-2.25 turns out the air/fuel screw and stock is 148, you need a 150-152. Buy them here: http://www.jetsrus.com/a_jet_kit_atv/honda_400_TRX400EX_1999-2008.htm

[pdanko]

what type of internal motor issue could it be? so if the a/f screw doesn't cure it is adjusting the needle hard? and if half choke fixes it what does that mean? really got me baffled , thx again

[CJM]

Theres no motor issues at all, your carb is probably dirty (still) and it needs to be jetted right.

[pdanko]

k thx i will try to clean it change jets this wknd . will let you all know

[CJM]

Take it apart fully, bowl, accelerator pump etc and clean all passages with carb clean and scrape any gunk out.

[pdanko]

haven't cleaned it yet but tried the a/f screw out and half choke thing and did nothin different.

[powerbomb400]

Did it start acting up all of sudden or has this been building gradual?

[pdanko]

all the sudden, was making a high pitch rattle at a little past half throttle plus, thought it was the valves but they are fine? and then it started actin up shortly after that