more help with 250 sx

[will1806]

Well my 250sx still isnt running. heres the situation. i have a good spark. new spark plug. clean tank/petcock. i have two carbs an atc 250 sx carb and a trx 250 carb. both i took apart and clean thoughly, jets and everything. even usesd and air compressor. neither will get it started and all i can get is a little sputter if that. i tried to flood the engine and it wont. it is like it isnt getting gas to the engine. after i removed the plug it only had a little gas on it. i drained the carb and gas poured out of the drain on the bottem of the bowl. if anyone has any ideas on my problem please let me know.

[erectordale]

have you done a compression check

[jasonb01]

Are you sure you cleaned the bowl on the bottom of the petcock good? Mine did the same thing yours is doing and I found all kinds of crap in that bowl and that solved it. Sounds like you did that, but just thinking of answers.

[Dirtcrasher]

When it won't start, loosen the lowest screw on your carburetor fuel bowl - it will have a hose connected to it, or a place a hose should be on there. See if it drains for a bit, should be a few tablespoons worth of gas or it's not getting gas to the carburetor.

Has to be a fuel delivery problem...

Either something is restricting the flow or the intake valve isn't doing it's job.

Like Dale said, check your compression - no pressure gauge?? Just see if it blows your tightly fit finger off of the spark plug hole...

[will1806]

it has fuel in the bowl cause it does drain when i open the drain screw. i dont have compression check but it does blow my finger off the hole

[traxxasx]

try takeing your spark plug out put some fuel in replace spark plug and try it if it doesent run seems like timing.

[will1806]

i tried that in it sputtered a bit. how to check timing. and were to get a compression check

[will1806]

does anyone know if their is a difference between the trx carb pilot screw and the atc pilot screw on the same year model. becaues the carbs are made slightly different. i am thiking of going and getting that carb cleaning thing with the basket and maybe a new rebuild kit for the carb.

[Dirtcrasher]

THE STUPID BASKET DOESN'T WORK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Get a little manual and a nicely lit up work bench and a clean rag.

Unscrew every single jet, spray carb cleaner in them, soak them in carb cleaner and spray compressed air in there.

Yes, the airscrews are probably the same (350X is the same), must have a good intact oring. Don't lose the order of parts - screw,spring,washer and oring....

THATS THE ONLY WAY!!!!!!!!

Whats wrong with your screw?????

[will1806]

its off of a trx250 but inside the bowl they are different. slightly. one more question inside the bowl of the atc 250 carb you have five holes. the one for the needvalve. main jet. the other jet. what is the fifth one and its purpose. because the head is striped. and i havent fought to remove it yet. maybe thats my problem and how can i check to see if sufficent fuel is reaching the engine.

[poochie44]

have you checked to see if the needle moves up and down when you open throttle the needle jet may be at fault. pull the hose on the petcock and make sure the filter lets gas thru. If you know you have gas to the carb then concentrate on the carb.