Sputtering? stalling out

[brapbrap13]

ok. i just replaced the starter clutch, new gasket, flywheel, plug, and changed in the oil. everything came off and went on very easy. it started right away(it had been sitting for bout 5 weeks). i ran it around the block and it ran perfect through every gear idle and everything. this morning i go to take it for a ride starts right up let it warm up. get on and go. i get aout 6mins and it starts cutting out and it dies. i try to start it and it wont. so i wait 3mins and it fires right up and is cutting out the whole way home. wat could be wrong?

ALSO. the oil level was fine and there was no smoking or funny motor noises, it is getting plenty of spark.

[400excaleb]

Originally posted by brapbrap13
ok. i just replaced the starter clutch, new gasket, flywheel, plug, and changed in the oil. everything came off and went on very easy. it started right away(it had been sitting for bout 5 weeks). i ran it around the block and it ran perfect through every gear idle and everything. this morning i go to take it for a ride starts right up let it warm up. get on and go. i get aout 6mins and it starts cutting out and it dies. i try to start it and it wont. so i wait 3mins and it fires right up and is cutting out the whole way home. wat could be wrong?

ALSO. the oil level was fine and there was no smoking or funny motor noises, it is getting plenty of spark.

The same exact thing happened to me, it stayed like that for months and no one knew what it was, i put a new carb and coil, and more stuff and it never worked. what it was is the gas cap i had (tusk billet aluminium) wasnt letting enough air in or out so i put my stock one back on it and it ran perfect, or i did for the 20min of riding the road.

[wysse]

mabe old gas??

[400excaleb]

have you tried anything to find your problem

[brapbrap13]

fresh gas. new plug, cleaned the airfilter. same deal. it will be good sometimes then others it wont. it doesnt stall out but sputters some times at wot. like it needs to be re-jetted? but i never changed the jetting and it ran fine a month ago. any other test i should run?

[400excaleb]

Originally posted by brapbrap13
fresh gas. new plug, cleaned the airfilter. same deal. it will be good sometimes then others it wont. it doesnt stall out but sputters some times at wot. like it needs to be re-jetted? but i never changed the jetting and it ran fine a month ago. any other test i should run?
im telling you, the exact same thing happened to me and i just got it fixed saturday. i have a tusk gas cap and it wasnt getting enough air throught it so i stuck my stock one back on it w/ no hose and it ran perfect.
so see if you gas cap is stopped up. (also what does wot mean)

[knelson]

Wide Open Throttle. are you getting gas to the carb?what do your plugs look like?Water in gas/carb? You may have to look into cleaning your carb. like stated before you may want to check your cap (even if it's stock, make sure the vent works)

[400excaleb]

i know it cant be somthing wrong in your carb cause i bought a brand new carb and put it on mine and it still does it until i changed my cap.

[krt400ex]

Originally posted by 400excaleb
i know it cant be somthing wrong in your carb cause i bought a brand new carb and put it on mine and it still does it until i changed my cap.


if he has a stock cap, then that is not his prob.

try leaning out the jetting a little. if it stutters on top it is usually running rich.

[knelson]

why does that mean it can't be his carb exactly? it all boils down to fuel starvation! also known as running out of gas, clogged carb jet, clogged fuel filter, clogged fuel tank vent,etc,etc...

[knelson]

I've seen stockers fill up with dirt, don't mess with jetting until you have rule out possible problems (all that does is mask the probs.)

[krt400ex]

Originally posted by knelson
why does that mean it can't be his carb exactly? it all boils down to fuel starvation! also known as running out of gas, clogged carb jet, clogged fuel filter, clogged fuel tank vent,etc,etc...


agreed^^^^^


but if it is low on fuel it usually will stutter off the bottom and still rev fine until it just dies

[knelson]

that would be because you have an accelerator pump that does not use venturi to operate, It's kinda like a squirt gun (for bottom boost)

[krt400ex]

Originally posted by knelson
that would be because you have an accelerator pump that does not use venturi to operate, It's kinda like a squirt gun (for bottom boost)


yup, and the ex has an accelerator pump and every aftermarket and FCR has an accelerator pump. this is why i don't think it is his prob. it could be, but i don't think that that is all

[400excaleb]

Originally posted by knelson
why does that mean it can't be his carb exactly? it all boils down to fuel starvation! also known as running out of gas, clogged carb jet, clogged fuel filter, clogged fuel tank vent,etc,etc...

ok, well the exact same thing happened to mine, in would sputter and pop at high revs and it would just die and wouldnt start for a minute or so then when it did it would pop and stall and die again. i had the carb worked on, re jetted, cleaned out and when none of them things worked i just decided to go buy a new carb to fix all the problems but it didnt. so i took it to get it worked on and the honda dealership and they told me the tank wasnt getting no air and it fixed all my problems.

[brapbrap13]

wow. thanks for all the input. i never got this much. haha all try some stuff out tomorrow and see how it works. when i changed my plug it was black and little brown.

[Eviltanker]

Black and a little brown isn't too bad. Check the fuel path like 400excaleb said I had the problem a little bit at first with mine. Changed the vent tube to a breather and problem solved. Start cheap and work your way up. .02

[-copyguy-]

you can pull the petcock out of the gas tank and check the strainer too...It's probably a clogged main jet though. If it was running fine and now it's bogging, it's probably the carb. justg my .02 though...

[knelson]

Originally posted by krt400ex
yup, and the ex has an accelerator pump and every aftermarket and FCR has an accelerator pump. this is why i don't think it is his prob. it could be, but i don't think that that is all
I meant the reason it studders is because the pick-up port for the accelerator pump is at the bottom of the carb bowl Thus, the reason it will rev but not run "
Originally posted by krt400ex
it is low on fuel it usually will stutter off the bottom and still rev fine until it just dies

[400excaleb]

My bad you guys, after all i said about the gas cap it still does it, it ran perfect when i did it but now it dont.

this is what all i have tried, cleaned carb, rejetted, bought new carb, cleaned gas tank, changed coil, took carb of a good running and jetted 400ex and put on mine and everytime it does the same EXACT thing as you stated above, if you got yours fixed please help me.

[krt400ex]

Originally posted by knelson
I meant the reason it studders is because the pick-up port for the accelerator pump is at the bottom of the carb bowl Thus, the reason it will rev but not run "


i am not too sure i understand what u mean....

[knelson]

Sorry, just trying to explain. Did you ever figure out your problem?

[brapbrap13]

no, i have taken the whole carb apart 4 times cleaned everything. still doing the same thing, it goes to the shop soon. then gets put infrront of the shop with a big forsale sign. every atv i have owned is a huge headache, i have had the worst luck.

[400excaleb]

i havent fixed mine either, i no one thing and it is a true fact, it is nothing in the carb, I bought a brand new carb and that didnt fix it, and took the carb of another 400ex and it still did it. i guess mine will go in the shop too, unless yours goes first and it can be an easy fix.

[krt400ex]

check for leaks in the intake boot between the carb and head. if it is sucking air then it will do that. even if u can't see anything, i would replace that and see if it works.

[400excaleb]

Originally posted by krt400ex
check for leaks in the intake boot between the carb and head. if it is sucking air then it will do that. even if u can't see anything, i would replace that and see if it works.
so you say to replace the whole intake boot or what.

[krt400ex]

the boot between the carb and intake port. not between the air filter and carb.

[Ncboost]

See what the compression is and do a leak down test.

[hondaredrider]

mine did that to me while i was riding, man that sucked big time. so i checked everything out, drained the gas, and put fresh 94 octane and it hasn't done it since. as gas sits it loses it's octane, i would drain the gas out and put fresh in.

[knelson]

If you have a air leak in the intake side, try spraying some carb cleaner around around the boot and its connections, If it is an air leak the motor will rev.

[400excaleb]

i dont know if this is the same problem but know mine wont even start, it has no spark and i have changed the coil, plug and rev box and still no spark. there is no loose wires.

brapbrap13 if you would, can you go ride yours till it dies and then check to see if it has spark when that happens.

[DEAL]

some advice - the stator plays a big part in the way the bike runs..

[400eXr1d3rZ]

Look inside of where the gas cap rubber hose goes (steering stem), it could be filled with water, this was said in another thread, and that could be starving it. Pull the hose out of the steering stem and try to run it like that.

[400excaleb]

Originally posted by 400eXr1d3rZ
Look inside of where the gas rubber hose goes, it could be filled with water, this was said in another thread, and that could be starving it. Pull the hose out of the steering stem and try to run it like that.
what rubber gas hose are you talking about

[400eXr1d3rZ]

Originally posted by 400excaleb
what rubber gas hose are you talking about

The one on the gas cap, it gets fed through the steering stem.

[400excaleb]

Originally posted by 400eXr1d3rZ
The one on the gas cap, it gets fed through the steering stem.
i took the whole gas cap off and rode it and it still died. its something electrical.
i got mine to running. i think there is a short in the wires going to that stator or the rev box is our problem, or maybe the whole stator

[400excaleb]

i fixed it. it was the stator.