Dirty Carburetors? Nope! What could it be

[ROSS11988]

I bought a used 2009 Ninja 250 in Feb. Girl owned, 2800 miles, no problems. Just mentioned the carburetors need to be cleaned out. You would have to have the choke on to keep it from stalling. Rode home, no problems. Went away for a month came back and it wouldn't fire up when I came back. Only way we could get it to start was by spraying starting fluid in the side of the air filter. So we take it apart and the carburetors and they were immaculate, i mean absolutely nothing on them, we cleaned all the jets and the floats anyway. Bike seems to work a bit better after replacing the gas and adding seafoam, but still stalls out. Any ideas?

Attached is a video I just took. Added Seafoam to it as well. http://youtu.be/F7Bvlc74MCw

[Skullz]

Have you tried replacing the old gas with fresh gas yet?
I would try that first before trying to diagnose other potential problems.

[dcj13]

Originally Posted by Skullz

Have you tried replacing the old gas with fresh gas yet?
I would try that first before trying to diagnose other potential problems.

Yes! Definitely! Put in a half gallon of fresh gas and about half an ounce of Seafoam or Gumout. Get the bike running (use the starting fluid if you have to... even if you need to keep spraying a bit to keep it running at first). Run the bike this way for 10 or 15 minutes, restarting, goosing the throttle, using the choke as necessary. Tap the carbs with a screwdriver handle or dowel or something similar.

It might get better right away: if so, great! If not, let the bike sit overnight and try it the next day. The Seafoam/Gumout will have had a chance to soak into any crusties in the carb and loosen them up. Repeat previous day's activity.

This technique can work wonders on small 2 and 4-stroke engines.
(As I type, a buddy is on his way over with a weedwhacker that hasn't run for a few years . Guess what I'm doing this afternoon?)

[flitecontrol]

I'll preface this by saying I haven't been into the Ninja carbs yet, and hope I don't have to. But I've cleaned a bunch of other motorcycle carbs. Some were so varnished up or full of tank rust that it's obvious they need cleaning when you open them up. But there are carbs that aren't obviously dirty that also require cleaning. If the jets or any of the internal passages are blocked, even partially, the engine won't run right.

Sea Foam is not an aggressive carb solvent. It can't clean a really dirty carb, but can help loosen up light deposits. If you want to try using Sea Foam to clean a carb, I suggest adding it full strength to the carb. First, drain the carb and tighten the drain screw. Then disconnect the fuel line from the petcock. Using a very small funnel or syringe (free from my vet) add Sea Foam through the hose until the carb is full. I'd recommend you let it sit 48 hours or more. Then, drain it out as the engine can't start on straight Sea Foam. If that doesn't get the carb clean, it's time for Berryman's Chem Dip and a full cleaning.

[ROSS11988]

Well, we got everything put back together yesterday. Added new gas and it sounds much better. Looks like you guys were right, maybe just bad gas? At the same time we also replaced the spark plugs. God the 2009 Ninja is such a pain to take apart? This was Japanese made? My buddy said it still didn't sound right, but I thought it was good. Starts much better. Still needs choke, but after 30secs you can take it off. I bought Seafoam today and put an ounce in. Should I just let it sit in the can for a day or run it in between? Also whats the best way to clean the air filter? Gasoline?

[DaBlue1]

Originally Posted by ROSS11988

...maybe just bad gas?
....I bought Seafoam today and put an ounce in. Should I just let it sit in the can for a day or run it in between? Also whats the best way to clean the air filter? Gasoline?

Yes, gas can go bad in a matter of weeks, and on rare occasion in a matter of days (especially if the bike is left outside in the rain).

Run the bike as much as possible with the Seafoam in the fuel. If the bike idles rough, the pilot jets may need cleaning. If not, you're probably OK. Since the bike has not been run in a while, it will need to be ridden and warmed up good to notice any improvement. It's normal to need choke on this carbed bike especially in colder weather.

The best way to clean the air filter is with carb cleaner or very hot water and Dawn. Then dried thoroughly and lightly re-oiled. If the filter is old and looks compressed it may be time for a replacement. Kawi recommends replacement @ 2 years.

[ROSS11988]

Added a video in the OP. Can only be turned out with full choke, shoots straight up to 6 thru 7K. You get a white smoke, Im assuming from the Sea Foam. Turned the choke off, was able to rev it a little on the throttle then it suddenly dies. Any idea?

[DaBlue1]

Originally Posted by ROSS11988

... Any idea?

The pilot jets are clogged (and need manual cleaning) and the idle speed (idle adjustment knob) is set to high. If the carbs and the choke are functioning properly, the rpms should only go a around 3-4k rpms.

Your engine idle speed should be 1350 +/- 50 rpms. The engine should be completely warmed when it is adjusted.

2000-3000 rpms is a common idle speed range for when the choke is on. They key is reducing the amount of choke (small increments) during the warm up until the bike can maintain a steady set idle speed on it's own. It is also acceptable to ride off with the choke on a short distance until the bike is warmed.

Never let your cold engine idle that high with no load. The white smoke may be a sign of

Piston oil ring worn
Cylinder worn
Valve oil seal damaged
Valve guide worn
Engine oil level too high
Warm exhaust condensation (cold ambient air)

[ROSS11988]

Pilot jets were cleaned. We couldn't believe how clean the whole thing was. Still put carb cleaner through it anyway. I'll set the idle speed lower. I'm hoping the bike is just cold and needs to be ridden

[g21-30]

If you still have to use the choke, I say one or both carbs are still not cleaned. Try this

Link to original page on YouTube.

[jcgss77]

Rule of thumb-If you ever take the carbs out of the bike, and it has had any amount of time sitting, clean them. Ethanol is a king gummer of carbs. Try to run non-ethanol gas if you can, I am lucky and have one such gas station about 1 mile from my house.

[capt_bugaloo]

+1 for Seafoam. If it's just gunked carbs the Seafoam will help. I've used it on both motorcycle and car and it does work as advertised.