250x starts, runs for seconds then dies

[full foot notch]

well as the title states

i have a 1988 honda trx250x atv, have had it for a long time almost since it was new

well fast foward to current times, a few months ago, it was brought out of storage, and i had to get the carb rebuilt at the dealership and even got new either float seats or needle seats (i really dont remember but it was a seat that had to be installed in the carb), i also had to get a new fuel petcock for the tank since the original one finally went and was leaking thru the selector orings, well $150 later its up and running, and i take it for a test ride, and am going up and down the roads and fields and doing a few tricks like i use to do when i was younger

well near the end of the test run, the quad would cut out and die in gear, and i figured it was the spark plug wire (have had to put a ring terminal on the end of the spark plug wire because the oringal connector came off during one tune up and the dealership wanted too much money for a new box, and this ring terminal has worked for a while, well i got it running again and put it away for a while, while i was getting new tires for the front, so fast forward to today, when i sold it to a buddy, and he picked it up. we get it to his house and get it kick started (this model is kick start only, no electric start), well we would get it started and it would run for a few seconds (say 5 seconds) with a little thumb throttle, and then it would die out, not like a sputter, but like someone moved the engine kill, and then i would kick it for a few more seconds, and then it would do the same five second run and die, while idling and quick reving up i could let the clutch out and get it somewhat down the driveway and then would die on its own.

i also checked the oil to make sure the motor didnt have some low oil cutoff sensor, i know it has air fuel and spark since it will kick start and run, and it also has a brand new K&N filter on it, and its one of those i think its the carb, but if i had it rebuilt within the last three months it shouldnt be doing this

its confusing the hell out of me

[full foot notch]

also, dont know if it matters, but once started, even giving it gentle throttle and varying the throttle, will only work for that 5 second period and then will die

[cmpearce]

check the vent hose on the top of the gas tank some times they plug up.also check the air filter system .i just cleaned a mouse nest out of a buddy's quad .a mouse can build a nest over night.also if the quad sat for a while you could have built up varnish that came loose and worked it's way into your carb. try some spray in carb cleaner .

[full foot notch]

could the vent hose or gas cap be bad and not let it vent, causing a vacuum within the tank?

as for the air filter, the air filter was ordered the same time the carb was rebuilt and all the hoses were blown out all the way up to the head, with the hoses off the quad, so i know its clear and no trash in the hoses and head

so would it be best to empty the tank and spray tank down with carb cleaner and then carb cleaner into carb? id rather not have to since the carb was rebuilt, so it seems redundant, but idk

[Kickstarts-suck]

change your plug 1st.(not sure if you ever have) and take the carb apart and clean it out with some carb cleaner(take the jets out and clean them too)

Also sounds like you need a new coil. I have one ill sell cheap.

here is the link to all the stuff im selling
http://www.exriders.com/vbb/showthread.php?s=&threadid=283200

[the Z Man]

Put it on reserve.

[full foot notch]

what will putting it on reserve do? ie what will it bypass or accomplish

[bwamos]

Since the most recent thing worked on/changed was the carb, lets start there.

Check a few things.
Make sure all vent hoses on the carb are not crimped. Needs to flow air freely.

Take off the gas cap.. and start it up. If it still dies, it's not the gas cap vent tube.

Check to make sure the choke isn't slipping back to the closed position.

Make sure that something on the carb didn't wiggle loose. (jets, etc).

Also while the tank is off.. remove the plug from the bottom of the petcock to make sure the filter didn't get clogged. Just put a new one, coulda got a piece of loose teflon or something in there.

Sounds like you're getting too much fuel though, and loading up the motor.

Overflow/vent tubes are pointed down, correct? They shouldn't go up. should go down along the frame down toward the swinger.

Also doublecheck that the slide didn't come loose from the arm. (check from the top). If it did, the slide drops down below the idle position and the motor wont idle, or rev up. (kinda sounds like your issue).

[full foot notch]

hate to sound retarded but which part exactly is the slide (ie visually looking at it

but the thing is, is that i can rev it up, but then it dies, like it has only so much fuel in a specific location and uses it and then just shuts off, does not spit and sputter

[m.h.s.c.#527]

go thruogh all of ur fuel lines and then c if theres sumthin nasty in ur tank

[full foot notch]

well today, blew thru the gas cap, so i know thats clear, both of the vacuum vent lines to the top and bottom of carb are blew thru and they are cleared, cleaned out gas tank, checked petcock filter, looked brand new, installed new NGK spark plug gapped at 30, checked the spark with the wire off to the block, shocked my buddy pretty well, then it got dark and so we quit for the night

[full foot notch]

when i pulled the plug it was black, but really didnt smell of raw fuel, the new plug, it seems to kick over a lot easier like there is there is blowby compression, its not all the way bad, when slowly cycling kicker with hand i feel the compression stroke, its just when kicking it comes down a lot better than before where it was like hard kick down