Hello everyone. I have a 2000 Ninja 250 which I bought about 2 seasons ago. I have only gone about 200 miles and it now has just 2150 original miles.

As long as I have owned the bike, it has had trouble idling. However, now that I have searched the net (including this site), I found that the factory idle is set to around 1300 rpm but people have better luck between 1500 and 1800 rpm.

This season, the bike became very difficult to ride. I only took it out in June once to go about a mile each way to get inspected. I was surprised they passed it considering I couldn't take it off choke.

Anyway, the bike sat since then until now. I purchased some of the carb cleaner additive by Stabil, put it in the old gas. Didn't help. Let it idle a bunch with the choke on and even took it out for a ride.. both with and without the choke on (including everywhere in between) the bike had a very hard time going anywhere. I had to keep it above 8000 rpm to keep from decelerating. Also, when getting on the throttle I had to be VERY slow or it would die. Often it would surge down, catch itself, then climb to where the throttle was positioned.


After that, I decided to be a little smarter (I hope) and check some things out, rather than going for the quick fix I was hoping that little 4oz bottle would give me. I did the following...
1. Pulled the plugs, they looked great (tan) and they looked the same. They were gapped at about .023 so I regapped them to .026 as that seemed to be what they should be at based on some searching the net.
2. Drained the tank through both the regular and reserve ports.
3. Pulled the air filter and cleaned it, had some fuzz on it. Now it's all clean, but it wasn't dirty enough to be an issue.
4. Drained both bowls via the allen bolt on the bottom.
5. Reseated all wires on both coils.
6. Looked for the fuel filter which the internet suggested was a plain screen on the inlet of the carb. However, I do not see one there (could be a reason for the carbs to be dirtier than the extremely old gas made it).

Filled it back up with some 91 octane and added another bottle of that Stabil cleaner. Let it run some more, still wouldn't idle. The hesitation when I turned the throttle was nearly gone. The RPM didn't instantly go up, they sort-of stayed where they were then climbed. This is an improvement over the condition above. Took it for a drive and it is still stumbling and was only ridable above about 8000 rpm. The bike felt like it wanted to go for an instant, but then came back down to being sluggish. If the plugs didn't look the same, I would think i were running on only one cylinder most of the time.

The bike really feels like it is misfiring. I just can't figure out why as the plugs look the same. Is there something I can move to affect timing.. perhaps it has misadjusted itself from vibration?

I would like to avoid taking the carbs apart, as I am afraid I won't be able to get it back together successfully and then I will be left with a bike that won't run at all.

Any help would be awesome! Thanks.

 

Sorry brother but it sounds like your gonna have to dig into the carbs. carb cleaner additives cant clean everything, and they gotta be cleaned inside and out. Its not hard but it can be scary. Find someone who has done it before and have them help you out. The manual and parts diagram will be a big help too.

 

quality gas is a big thing with the 250's and the 500's

stabil may work with fresh gas after lets say a 300 mile ride. None of those short rides though. Otherwise just pull off the carbs every ride since you do not ride much. the ride needs to be ridden! Bad gas and run issues for my 500 is within 14 days.

 

I'd like to ride more, but the bike has just never ridden steady enough for me to feel safe on the road with other cars.
I've seen the diagrams of the carb, but I'm concerned about O-rings or something tearing as this engine is 10 years old during disassembly.
What exactly would I be cleaning once I had the bowl off and what would I use to clean it? Does anyone have a link to a minimal teardown/cleanup which doesn't necessarily include a full rebuild of the carbs?

 

Flush the gas, drain the bowls, place fresh fuel in and you and a buddy go riding for the day. I had to use stabil on the 500, adjust the idle up to keep it running, ran the bike maybe 100+ miles before the stabil worked. Readjust the idle, then everything was golden. But since you are unsure, take it to your trusted mechanic to prep it for you.

 

Thanks for your comments Dragone. I appreciate your experience with my type of situation.


After the 100 or so day of riding, did the bike suddenly "wake up" or was the improvement something you could gradually notice until it was "back to normal" again?


Do you think there would be any benefit to spraying carb cleaner in through the air filter openings (removing the air filter first of course)? Should the bike be running or not for this?


For additional information, I can not get it to idle at all right now without the choke on. While riding at 8k+ rpm, I need to be at around 75% throttle to maintain speed and full throttle to gradually accelerate.


Thanks again,
-Jess

 

Change the spark plugs, & inspect the condition of the spark plug wires / boots. If your spark plugs look badly overheated (white) or damaged by a lean condition (see attached chart), stop here and have the bike fixed by a professional if you can't work on carbs yourself. If your jets are plugged, not enough fuel is getting to the engine. This means the bike is running lean and you can do severe damage by running it in this condition. If your spark plugs appear tan or sooty black, you should be ok.

http://www.theultralightplace.com/sparkplugs.htm

Check / clean the air filter if it's dirty.

Drain the tank, drain the carb bowls, button it back up. Fill it with fresh 87 octane gas, and dump in an entire can of Seafoam. Crank it up, take it for a ride, and park it on the center stand when you're done riding for the day. Shut it off. Repeat. Repeat. Repeat.

After my 3rd tank of 'Seafoamed' gas, my Virago cleaned up its act without removing the carbs. Hesitation, backfiring, etc. stopped. Yours may be dirtier than mine was, but it can't hurt to try this method if you're not well versed in carburetor removal and repair.

 

I would recomend trying Seafoam first also. You have something plugged up in the carbs, but they are difficult to get out of this bike. Don't put a full can in, but add per instructions or it won't run at all. Then ride your bike and see if it clears up after a tank or two. If you are going to leave your bike parked start keeping stabil in the gas. I think it is easier to just ride regularly.

 

No substitute for getting boogers out of the jets. I'd pull them off and do it right. Sometimes additives can do more damage than you think, and still not solve the real problem. Don't crap up everything trying to take the easy route. It will likely save you time (and maybe money on miracle potions and their effects) in the long run. But, I realize it also depends on your mech skills and toolbox.
My 2 cents.