02ninja 250 stalls when coming to a stop or when reving in neutral

[Catchandrun]

Is it just the idle? I've cleaned the carbs and the the jets and there has been no change except now it's leaking a little gas at the top end of the petcock to carb tube. I would change the plugs but I've lost my plug wrench and I really don't think it's the plugs anyways but Idk. Also when I took the carbs off the first time I noticed that my air filter wasn't even connected to the carb could this cause any problems? Lastly the rpms seem to stick just a tad when going down from time to time. All help is greatly appreciated.

[Ghostt]

Make sure the airbox, and cylinder boots are properly installed.

What is the idle currently set @?

Have you done a valve adjustment? Or checked them?

Where exactly is the fuel leak? If you petcock is bad, it could be sucking fuel thru the vacuum line.

Test the petcock, if it bad, order a new one.

[Catchandrun]

Originally Posted by Ghostt

Make sure the airbox, and cylinder boots are properly installed.

What is the idle currently set @?

Have you done a valve adjustment? Or checked them?

Where exactly is the fuel leak? If you petcock is bad, it could be sucking fuel thru the vacuum line.

Test the petcock, if it bad, order a new one.

The airbox and boots are good the idle is @1300-1500 it like to bounce a little. the peacock is,good but it,seems when the fuel goes to,the carb from the tube it's,overflowing just a little from the top of,the tube where it meets the peacock not to big a deal I think because it's only a couple drops when I first start it up after,that its,good, but I thought that could of been a symptom of the bigger problem I'm having

[Catchandrun]

Also no valve check or adjustment when and y though, would I have to do this

[VaFish]

Originally Posted by Catchandrun

Also no valve check or adjustment when and y though, would I have to do this

It's a routine maintenance item every 6000 miles.

[Ghostt]

Okay fuel leaking is always a big deal! Find it, and fix it ASAP, for your own safety at the very least.

I'm sure the others will agree.

Valves out of adjustment will effect idle, and performance. It's one of the most overlooked service items.

[Motofool]

Originally Posted by Catchandrun

........ the idle is @1300-1500.......

Welcome, Greg !!!

Simplest thing is to increase that idle rpm's some, like 1.6 to 1.8 K rpm.

Did you clean the idle circuit in the carburetors?
New o-rings for the needle valves?

[Catchandrun]

So I just put the idle up to around 1800-2000 is that too high? But anyways that didn't help it at all. It seems to run perfectly fine now at idle and while riding except I can tell when it is about to die when I'm riding because there is a short stutter in the throttle while I'm riding and I know if I stop the bike will shut off. Also idkI if this changes anything for the valves but it only has 2500 miles on it so please let me know on that. I didn't check the orings for the idle screws but I took them out and soaked them with carb cleaner and sprayed cleaner all the holes where they screw in. I really don't want to take the carbs back off unless I have to. so do I have to check the orings first? Also when the bike shuts off it won't start for about 10 mins and only will run with the choke on until I ride for a couple mins idk of that helps but I guess it doesn't hurt btw too the idle screws are set to what they were for the past 2 years before the bike ever had this problem

[Catchandrun]

The needle valves are the idle screws right?

[Motofool]

Originally Posted by Catchandrun

The needle valves are the idle screws right?

Yes.

Originally Posted by Catchandrun

So I just put the idle up to around 1800-2000 is that too high? But anyways that didn't help it at all. It seems to run perfectly fine now at idle and while riding except I can tell when it is about to die when I'm riding because there is a short stutter in the throttle while I'm riding and I know if I stop the bike will shut off............ Also when the bike shuts off it won't start for about 10 mins and only will run with the choke on until I ride for a couple mins........

I don't know if your problem could be electrical or just improperly cleaned carburetor or fuel delivery.

The intermittent way in which it shows up makes me think that it is more the other two than carburetor related.

For electrical: Check all the connections of the battery and the two spark coils and wires-boots.

For fuel delivery: Check that the cap of the gas tank is letting air flow in and that the vacuum hose to the petcock is not leaking air in.

Now, you can reduce the idle rpm's to normal, since 2K is not doing anything to avoid stalls.

[RacinNinja]

Carb vent hose sounds plugged or pinched to me....hence the waiting 20 minutes and having to run on choke.

Low fuel in the bowls.

Or petcock....or vacuum hose to the petcock has a leak.

[Ghostt]

Tank vent ?

[RacinNinja]

Originally Posted by Ghostt

Tank vent ?

Yeah, this one too!

[Catchandrun]

Thanks for help everyone i probably should of mentioned this earlier but I had to buy a new gas cap (off eBay from china) so where would the tank vent be? Also where is the carb vacumn hose

[Catchandrun]

Sorry I meant carb vent hose?

[RacinNinja]

Originally Posted by Catchandrun

Thanks for help everyone i probably should of mentioned this earlier but I had to buy a new gas cap (off eBay from china) so where would the tank vent be? Also where is the carb vacumn hose

Tank vent is in the gas cap.

Easy test. Loosen the gas cap after it dies....if you hear a hissing sound, the gas cap isn't venting properly and creating a vacuum, restricting fuel flow.

[Ghostt]

Originally Posted by Catchandrun

Thanks for help everyone i probably should of mentioned this earlier but I had to buy a new gas cap (off eBay from china) so where would the tank vent be? Also where is the carb vacumn hose

The OEM gas cap has diaphragm vent, most aftermarket ones don't have a vent, so the tank doesn't vent, and gas can't flow.

To verify this try loosen the cap, or just open it, allowing the air back into the tank, if the bike starts and it's okay, you found your problem maybe.

Here's my write-up on the vent issue


Sounds like it could be a venting issue, no worries it's a free and easy fix,

You need you to disassemble the gas cap and remove the two small red diaphragms, assuming this is your only problem.

The diaphragm gets hard and losses it's flexibility and gets stuck, and doesn't allow proper venting.

IMHO this modification should be done regardless to prevent future problems whatsoever.

They are ment to vent the tank, but in the case of an accident not allow gas to leak out, but more often cause problems then they fix.

Here are some pictures to help you.

The plastic piece houses the two small red diaphragm pieces, this one being mine, they are already gone, and you can leave the plastic piece out all together, as I'm going to do now.

Some things to watch out for are, there are 5 small springs under the round collar, and a small round collar as well on the locking mechanism, don't lose any of them.

Good luck.

[Catchandrun]

Also I cleaned the carbs very good the only thing it could be regarding the carb is the float bowls because all jets were cleaned to perfection but I didn't touch the float bowls. Would the bowls cause this problem? How do I check to see if the carb vac hose has an air leak.