Ninja 250 Owners - Need Your Help

[rwalterk]

As you may have seen, my bro just got a 2003 ninja 250.  It only has 2500 miles but it's been neglected and wasn't running that well.  We changed the oil today (nasty) and got fresh 91 octane gas running through it and it runs so much better.  The only problem is that it hesitates badly from idle and anywhere under 3000 RPM.  Anything above 3000 is great though.

We tried playing with the idle adjuster but could never get consistent results.  Sometimes the idle would get stuck at 3000; other times it would dip all the way to 1000 even with the adjuster in the same place.  We played with it for a while but realized we weren't getting anywhere.

Anyone have any suggestions?  Neither of us is any good at working on carbs but I get the feeling that's where it's going, as in the carbs might be gummed up.  I've also read that putting Sea Foam through a couple of tanks of gas could clean the carbs out.  Any insight would be helpful.

Thanks,

Ray

[JimT]

I know how much you hate carbs Ray, but I think you are going to have to take them apart and clean them.(or pay someone to do it)

That few miles the bike must have sat forever. You might want to consider a jet kit as well, the bike was probably set up to run super lean from the factory.

[zerog]

Yes, like Jim said, you are going to need to clean the carbs.  And I am sorry for that Ray, if the bike still has its stock air box.  That thing is a nightmare to take out.

Oh, also, there is no need to waste your bro's money on 91 gas.  The bike runs fine (and probably even a little better) on the 87 gas.  There isn't enough compression in this engine to cause any problems with 87, and the 87 has a little more punch actually, not sure if it's much noticeable though.

[pshaw118]

I've read some really good things about sea foam.  Maybe you should give that a try before tearing anything apart.  So when's Judd coming out to show off his new 250?

[Jon_W]

I'm sorry to say it, but I'm afraid I have to agree with the others regarding the carb cleaning...
(Though I haven't heard of the seafoam until now, so I wouldn't definitely give it a try.)

I had a 2003 Ninja 250 prior to my SV and rode it all the time.  I never had any problems with carbs, etc., on mine, but we bought my wife a 2004 Ninja 250 with 4500 miles or so.  At first it ran fairly well (but never as good as mine, in my opinion), but then she let it sit a long time.  Unfortunately, I didn't make myself ride it because I enjoyed by SV too much...

Anyway, we had a lot of trouble getting it to idle correctly.  One minute it seemed like I got it set close to 1300rpms, the next minute it was revving to 5krpms.  She pretty much had to run it with the choke on to keep it running.  Even warmed up, it would die at the stop lights.  Then with the choke on, it would rev high on takeoffs and be very abrupt in taking off as a result.

The final straw was when we decided to go for a ride, and due mostly to high-revving due to the above problems, it took off really fast when she let the clutch out, and she paniced which caused her to lay it down leaving our driveway.

Fortunately, there was hardly any damage.

I took it to Mountain Motorsports in Ontario (since I didn't want to do the carbs myself, plus it was time for the 6k service).
Here is the run down of the bill:
Oil Filter Element  $8.78
HGK Plug (2)       $4.14
Service Oil           $14.97
Intake Clamp       $5.18
6k mile service plugs & valves $200
Carb clean   $200
(Tech performed 6000 mile service - carb clean (actually they said they ended up cleaning them twice) and replaced intake boot clamp on carb.)

After a 10% discount, the bill came to $394.15

The result: Her bike runs great - actually probably runs as good as my 2003 did.  Now we just have to choke it for a block or so and then it no longer needs any choke the rest of the day (assuming it's warm outside and it's not sitting for long periods of time between rides).

I hated paying the price, but it was definitely worth it.  I just wish I had done it before she layed it down and ruined her pride. 

[rwalterk]

Thanks for the advice everyone.  Jon, those are almost exactly the same symptoms we're having.  Looks like we gotta do the carb cleaning... ugh.     I'll have him try the Sea Foam first though for a couple of tanks of gas and see if that works. 

If not, it's off to carb cleaning time.  Yay!  <---sarcasm

[pshaw118]

Good luck getting everything fixed.  Judd must be totally bummed that his new bike isn't running right.  BTW, let me know if he needs any gear.  I have a couple of pairs of textile pants that I'm not using anymore.  He's welcome to them if he wants them.

[Cammie]

Ray,

If I'm remembering correctly, the Ninja 250 board has a tutorial regarding cleaning carbs.  Also, you may want to give Robert (Racinteach) a call......he could clean the carbs for you.

[AP]

Taking out the carbs with the stock airbox is not so bad.
I managed to get it out, uncap the epa idle mixture caps, turn them 2.5 turns out and put in all back together in one afternoon.  Makes it start and idle much better.

The trick is taking out the battery and the bolts holding the air box to the frame that are under there.  Unclamp and take off the rubber boots from the airbox and engine side and then you push the airbox back slightly all that it can move.  Other than that you just take off the choke cable, throttle cables, and the fuel lines.   Of course, before everything you have to take off the fairings and the tank. 

You might want to check and adjust the valves at that time too since almost everything is off.  Would not hurt to synch the carbs before you put back in but at that point is just extra.

I would first drain the float bowls and see if there was no water in there and that it has fresh gas.  87 should be all you need to use.  Then if it still continues take the carbs out clean them, adjust idle mixture screws, and might as well do a valve adjustment.

Might as well look at what tires are on it as well.  Replace with better tires if they are Dunlop K630.

[JC]

Don't rejet. It's not worth the effort for the gain you'll get.   Run the STP fuel treatment through a couple of times, and if it doesnt improve drain the float bowls and see what kind of gunk comes out. If its rusty or the gasonline has little blobs in it you will in pact probably need to clean them.  I have carb cleaner spray and dip at my place if you want to try and DIY, otherwise take it to the shop.

[amarilloNino]

hey guys, thanks for the tips.  Jon, that sounds exactly like what my bike is doing now.  dies at stops, revs super high on restart, almost guaranteed to die with no choke even when the engine is warm, inconsistent idle, etc.  and yes, the faster-than-comfortable takeoffs because of the high revs.  i'll give the sea foam a shot this week, and if there's no improvement then i guess i'm looking for someplace to take it to have the carbs cleaned.  any suggestions?  not sure if i have the time/patience/know-how to do it myself.

[rwalterk]

I already PM'd Robert from socalsvriders; he says he's familiar with the ex250 carbs and can clean them if the sea foam treatment doesn't work.

[Jon_W]

I wish I would have thought of Robert when we had my wife's 250 done...

I've had him do some things on my SV - FE, Tre, & radiator guard...  He's a great guy and it sounds like he can do just about anything regarding motorcycles.

[Cammie]

Ray, the shop teacher who worked on my CT90 carbs can have one of his students work on your bro's bike.  If money is an issue, this may be the most economical solution.  I can ask Bill for an estimate if you're interested.

[amarilloNino]

so, finally got my bike back today.  robert cleaned out the carbs, said one of the jets was completely clogged and that there was some rust in the bowls.  so he got all that stuff out of there, bike runs great now.  no idle problems, no stalling, no need to keep the choke on when i ride.  went for a quick ride with ray this morning, and the bike is handling and running great.  thanks for the advice guys.