'03 Ninja 250 won't run/idle

[SpecialED]

My wife's Ninja 250 started acting up yesterday. At first, it seemed like it was just having trouble getting warmed up (really low idle, would die immediately if you tried to move the choke setting or give it throttle at all).

After a few minutes of idling, the temp finally came up, and I was able to reduce the choke setting, and actually rev the bike without it dying. It seemed normal at this point, so she rode off for another 3 minutes, just slow neighborhood driving, and then it died again as she tried to get going from a stop sign. This time, it wouldn't run consistently at all afterwards.

It was very hard to start, but once it started, it would rev really high by itself (upwards of 6K rpm), but if you added throttle, it would bring the rpm down and eventually stall, like the function of the throttle had been somehow reversed.

I've been dinking with cars for quite a while, but I have no experience with motorcycles, or anything with a careburetor for that matter. Logically, I know to always start with the basics - air, fuel, spark. I'd guess it's NOT spark, since it does start eventually.

Air is rarely the issue unless you've somehow sucked a sock into the intake.

I'm guessing this is a carb thing? Unless there might be a simple fix, I have no desire to monkey with the carb. Should I even bother trying to change the spark plugs or wires before I drag it off to the Kawasaki dealer in Longmont? Does this thing even have a cap and rotor? *clueless*

BTW, while it hasn't been out every weekend, the bike has not been sitting completely idle. It gets out at least once every two weeks. It has just over 2,000 miles on it. The bike was dropped on its left side July 4th of this year, and it was sitting on the ground for maybe 10 minutes after the accident, but it hasn't had a running problem until now.

Any suggestions or input would be appreciated.

[TT5.0]

Sounds kinda like it might have a stuck float needle or something.

[Bat]

Dammitall - I just typed out a long, detailed reply and got tossed and lost it...grrrrrrrrrr!

So now you get the abridged version:
1. Goodly amount of gas? Petcock okay? Not being an ass or anything.
2. Pop that seat and check that the airflow is unrestricted (you'd be surprised, lot less than a sock will do it, including anything stored under there).
3. Check the choke cable system (that choke isn't stuck on) - the choke is getting turned off, yes?
4. Check the floatbowls/needles (although you are gonna have to pull the carbs to do this).
5. You get the carbs synched/valves checked at 500 miles? Do that if you haven't (even if this particular problem turns out to be something else). Can't stress this one enough.

This a one time deal or happening regularly now? A bad tank of gas with sediment clogging things up can cause problems until the crud is flushed out.

If you are mechanically inclined - consider grabbing a manual and doing this stuff yourself. 80's technology, a "simpler" bike to work on. A really good Ninja 250 forum out there with a damn fine FAQ to assist with all this. Also a coupla sub-par forums out there too, IMHO - the difference will be obvious.

Omg, this was the abridged version...bwahahaha!

[dapper]

Hey Hsun,
The carburetor area needs some tlc from the sound of it.

[SpecialED]

Thanks for the replies everyone.

Well, tonight I started it again. Fired up, ran with the choke off after a few minutes; seemed to be fine. Rode it up and down the street a few times, seemed OK - at least it would stay running and would rev normally. I ventured out into the neighborhood, and as soon as I was far enough away for it be really annoying to have to push it back home, it started acting funny, and then promptly quit and wouldn't start. Freakin' fabulous.

Since I was already halfway there, I pushed it to the closest gas station, and put about two gallons of premium in it. Not sure how much gas was in it, but it was definitely closer to empty than full.

It seems to run just fine now. Could it just have been bad gas? I usually just put 87 midgrade in the bikes. The Ninja's owner manual says "Use clean, fresh unleaded gasoline with a minimum Antiknock Index of 87."

Then there's chart that says the "minimum rating" is 87 by Octane Rating Method Antiknock Index (RON + MON)/2, or 91 by Research Octane Number (RON).

So what's the gas pump rating then - RON or RON+MON/2???

Well, in any case, I guess it gets premium from now on. Hopefully that's all it was. I'd hate to think that the carbs would get messed up with just over 2,000 miles on the bike (on a 2003 model bike too).

Bat: the air intake on this bike is under the SEAT? Why wouldn't it be up front, like on a real bike???

[Bueller]

Octane rating is not the problem, it will run fine on regular. "Fresh and clean" is your key words here. Probably should drain tank completely and start with all new gas.
Most real bikes have the air intake under the seat/tank.

[Sparker]

I had the same problem on a 96 250 i had. problem was in the carbs. mine was a little more drastic than yours but sounds just the same on a different scale. good luck dealing with thoes carbs! pain in the ass to get to.

[Bat]

Bat: the air intake on this bike is under the SEAT? Why wouldn't it be up front, like on a real bike???

Oh yeah - how absolutely SILLY of me to forget that I don't ride a "real bike"!!

+1 on Bueller's comments. No need to run premium. Sediment in the fuel sucks (speaking from my own pushing the bike experience).

And fwiw - see the holes? Make sure those aren't covered by anything stored under the seat:

[SpecialED]

Oh yeah - how absolutely SILLY of me to forget that I don't ride a "real bike"!!

Sorry, poor choice of words. My knowledge about bikes is very limited, but I was told (or read somewhere) that the design of the Ninja 250 and 500 have not been updated much since their inception.

Since my CBR600F4i appears to have air intake ducts up front in the plastic, I just assumed most newer bikes have air intakes up front for a "ram air" effect. Maybe they're just fake scoops, like muscle cars in the 80's. I have no idea.

In any case, thanks for the pic of the air intake tract under the seat.

[Bueller]

Actual intake is mostly up front, I thought you were talking about air box/carb location.

[lifeon2]

Actually sounds like there might be a little water in the fuel I had this prob with a gs500 and it turned out the previous owner had the hoses hooked up all basss akward easiest way to check that is the float bowl drain just loosen it and if you see water then there you go.

Most likely it is a carb issue

[SpecialED]

Actually sounds like there might be a little water in the fuel I had this prob with a gs500 and it turned out the previous owner had the hoses hooked up all basss akward easiest way to check that is the float bowl drain just loosen it and if you see water then there you go.

Most likely it is a carb issue

The bike has been fine since putting fresh gas in it, but thank you.

But now the left turn signal function has gone out - it won't stay on. It works fine for signaling right.

Is a turn switch failure typical for a 2003 year bike with less than 3K miles? Seems a little premature. It couldn't have anything to do with the fact that I replaced the left front turn signal with a non-OEM Ebay unit a couple months ago, could it?

Self-canceling feature if it detects too much amp draw or something?

[lifeon2]

check the bulb first
check and make sure the wires are connected solidly
check the wires at the signal
check the turn signal relay (go to auto zone etc. a bike shop will overcharge the chit ot of you)

and last although unlikely check the wiring at the switch

thats the order I would do it in, of course I should be telling you to bring to my shop

[SpecialED]

check the bulb first
check and make sure the wires are connected solidly
check the wires at the signal
check the turn signal relay (go to auto zone etc. a bike shop will overcharge the chit ot of you)

Would any of those issues allow the left turn signals (front and rear) to operate as long as you held the switch in the "turn left" position though?

The left turn circuit/lights work, they just won't stay on w/o holding the switch to the left position.

Thanks!

[lifeon2]

ok some of those would still allow you to hold it and make it work, pardon my unfamiliarity with the machine but does it have auto shut off on the blinkers? if so that would be something to check as well

[SpecialED]

ok some of those would still allow you to hold it and make it work, pardon my unfamiliarity with the machine but does it have auto shut off on the blinkers? if so that would be something to check as well

No worries, thanks for helping. No auto shutoff on the Ninja 250, the turn signals are supposed to stay on until you cancel them by pushing straight in on the switch. That's why I'm assuming it's a worn-out switch - unless there's a overload protection somehow, I believe it's a purely mechanical mechanism.

[lifeon2]

no problem, if you ever need work on it just let me know