please help!!! '95 with idle problems (pics) (vid)

[hobosmeller]

hey ninjetters's, I need help i have a 1995 ninja ex250 that has 8500 miles that had been sitting for a long time before I got it. the bike barely ran when I got it and the tank was full of rust. but it ran.

history since I've owned it:
now I've removed the carbs and cleaned them out.
the main and pilot jets were also removed(note: the main jet "holder" was not removed) but I clean those little jets very well .
I tried my best to remove as much rust as I could from the tank but there was still some left. I installed an inline fuel filter as extra protection.
also the petcock was replaced because the old one had the filters ripped and missing. the plugs and oil/filter change were also done at the same time. I also removed the CA emission devices in case there were unseen vacuum leaks.

on a cold start the bike will run but idle under 1k, but after it warms up a bit it will shut off. I can turn it back on but only by giving it throttle. once I let off the throttle, the idle sets at 3k and slowly creeps it way down until the engine stops running. but the bike will rev to the moon and back. I was able to rev it all the way to 10k and it sounded good and strong.
(if I mess with the idle adjustment screw[the one with the black knob] it will only rev up high but the engine will die if I try to back it out to bring down the idle)

I'm not sure what to do anymore, I've searched around for these symptoms with not much luck. here is a pic of the inline filter I have installed.

note: I'm in the process of finding a smaller filter in case this one is causing problems being that the fuel has to travel up. I don't think I could rev it to 10 grand if it was affecting the bike a whole lot. less gas is needed at idle and vacuum is stronger at idle.

and here is a vid of what the bike will do. the bike here had already been warmed up a bit and there's a rattle from the from clutch lever.

http://youtu.be/ZzpA9oMwd0U" TARGET="_blank">Link to original page on YouTube.

again, I'm completely lost and open to any and all suggestions and ideas.

[Motofool]

Originally Posted by hobosmeller

............
again, I'm completely lost and open to any and all suggestions and ideas.

An old bike new to you can be a nightmare to troubleshoot.
You need to be methodical.

Please, read these:
http://faq.ninja250.org/wiki/Troubleshooting

Try avoiding creating and inverted trap with all that hose, you may restrict flow by creating a pocket of air.

Valves way out of adjustment can make idle crazy.

[jschorr]

Clean your carbs again. Break them all the way down this time. It is probably the holes under the butterfly. The pinesole method works well.

Cider vinegar works on rusted tanks, it takes time but it works. I am running that filter too. I did a straight shot to the carb without the loop though.

Motofool is right so cut down on the ??? By doing all the things that need done before making guesses.

[hobosmeller]

thanks to you both, will try again and read through the FAQs to try to diagnose the issue

[DaBlue1]

The fuel system is gravity feed. Your fuel line is too long and filter too big, it needs to be shorter so your fuel does not have to flow uphill.

[csmith12]

^^^

[hobosmeller]

Originally Posted by DaBlue1

The fuel system is gravity feed. Your fuel line is too long and filter too big, it needs to be shorter so your fuel does not have to flow uphill.

is this better? lol
sorry for the huge pictures

[hobosmeller]

a little update: broke the carbs all the way down and cleaned everything, every passage way, cranny, and nook. put the carbs back and took my time to make sure everything was perfect. the bike starts right up but it's doing the same thing.

it will turn on rigt away with the throttle opened and the idle will jump up to 3k and stay there and slowly come down as the bike warms up. after about 2 mins the idle will have continued to drop until the bike is no longer running. it will stay running if the throttle is applied and will rev all the way to 10k easily.

the pilot jets are marked with a 38, are those the stock sized ones? and I'm kinda at the point where I just want to sell it because I need money and I don't have money to keep throwing at this thing

[Motofool]

Originally Posted by hobosmeller

..........it will stay running if the throttle is applied and will rev all the way to 10k easily............

See if you can change (open) the position of the butterfly by manipulating the idle know by the left side of the carbs.
The end of the cable coming from that knob should touch the little external plate attached to the internal butterfly.

[DaBlue1]

Originally Posted by hobosmeller

is this better? lol
sorry for the huge pictures

Ideal positioning

[hobosmeller]

Originally Posted by Motofool

See if you can change (open) the position of the butterfly by manipulating the idle know by the left side of the carbs.
The end of the cable coming from that knob should touch the little external plate attached to the internal butterfly.

I've messed with that knob a little, it doesn't seem to help though. either the idle will shoot up really high or the bike will turn off when I try to lower the idle

Originally Posted by DaBlue1

Ideal positioning

was recommended these by a friend, they can be found on eBay for cheap and will make sure the hoses aren't kinked

[hobosmeller]

just wanted to give more thanks to everyone who is replying in this thread, I really appreciate you guys taking time to reply.


I'm thinking I might have to hand over my bike to a professional to have them figure out what's wrong with it.

could a valve adjustment and unbalanced carb setup cause this?
and I don't wanna sound like an idiot here but all 3 times the carbs have been cleaned, the idle screw(the one that needs to be drilled out) has never been touched, is uncovering that screw part of cleaning out the carbs?

[Motofool]

Yes, yes and yes.

http://faq.ninja250.org/wiki/How_do_...n_the_carbs%3F

[hobosmeller]

Originally Posted by Motofool

Yes, yes and yes.

http://faq.ninja250.org/wiki/How_do_...n_the_carbs%3F

thank you so much for the help, Motofool. I'm gonna do the battery box mod today and take the carbs out again and try again.

[Motofool]

Originally Posted by hobosmeller

thank you so much for the help, Motofool. I'm gonna do the battery box mod today and take the carbs out again and try again.

You are welcome, Juan

Don't forget cleaning these secret passages:
https://www.ninjette.org/forums/showthread.php?t=147048

Then, for fine adjustment of the low-end carburation:
https://www.ninjette.org/forums/showthread.php?t=10246

[hobosmeller]

thank you for the links! so helpful!

but just so it's understood, can the idle screws get "clogged" up like a pilot or main jet could? if I were to remove them, do they also need to be cleaned like a jet?

[Motofool]

Originally Posted by hobosmeller

.........but just so it's understood, can the idle screws get "clogged" up like a pilot or main jet could? if I were to remove them, do they also need to be cleaned like a jet?

Yes, those are adjustable restrictions to the flow of fuel, while the jets are cheap ways of restricting the flow of fuel with an orifice.

Wherever there is a restriction, junk and gunk will accumulate with time.

Fight that frustration back by working on your bike and learning in the process.
Nothing bad can come out of that !!!

Again, you are welcome

[Ninjinsky]

What Jschorr said^
like this (I don't recommend throwing half a gallon of gas around though )

Link to original page on YouTube.

[triumphtriple]

Originally Posted by hobosmeller

thank you for the links! so helpful!

but just so it's understood, can the idle screws get "clogged" up like a pilot or main jet could? if I were to remove them, do they also need to be cleaned like a jet?

I have a similar issue. Been working on it for about a month now. Please update us if you resolve it.

[hobosmeller]

thank you again to everyone who replied and even viewed this thread, it helped me push through the annoyance of the trying to get the bike to run


a small update(in case anybody cares)

I cleaned the carbs following n4mwd's secret passages thread, a small amount of gunk came out but the bike is still doing the same thing with the exception of it won't idle at any rpm anymore.

I can idle the bike with the use of the throttle and keep it at ~1500 rpm for what seems ever but it won't stay. the idle adjustment screws are 2.25 turns out. also the bike won't turn on unless I have the throttle open.

last but not least, after trying to get the bike to run today, a small pool of oil collected at the bottom of the hose that connects the air box to the oil sump. it was very thin and smelled like gas. don't know what to make of that yet except for it means gas might be leaking past the rings .

[Motofool]

Originally Posted by hobosmeller

.......I can idle the bike with the use of the throttle and keep it at ~1500 rpm for what seems ever but it won't stay.........

If you can keep it steady with the handle grip, then your problem is what Post #9 describes.

That is all that knob-cable mechanism does: to keep the butterfly valves cracked open to the point where a stable idle is achieved.
Balancing the crabs is just fine adjusting that for each carb.

[PHMCS]

This sounds almost exactly like mine when I first got her. Was sitting a year or so with mostly empty tank. Tank was full of rust.

I pulled the carbs and cleaned them all out with carb cleaner and wire, put them back in, and ended up with a bike that would only run with the choke on.

Took the carbs back out again, and took every little piece I could out, then soaked in berryman B12 Chemtool for a couple hours -> rinsed -> cleaned with carb cleaner and wire -> Soaked with chemtool once more -> sprayed every passage out with carb cleaner. drilled out the idle screws, adjusted them, adjusted the valves, and she started right up. Synced the carbs after, and she's been fine ever since.

That tank was a pain though. After a thorough cleaning with aquarium gravel to scrub out the big chunks of rust, I cleaned it out and coated the inside with a Kreem coat kit, and aside from a slight peel near the top fill nozzle 7000 miles later, Things have worked fine.

The battery tray mod will save a ton of hassle, it was the first mod I made to mine and it has saved me much swearing.

Since your tank was rusted, have to made sure the petcock is working properly? (not clogged, not leaking into your crankcase)

In regards to the oil/gas in the airbox, was it a substantial amount? did it look fresh or old?

Have you had a leak down or compression test done on the engine?

[PHMCS]

Ah forgot in previous post:

If you open your oil cap does it smell strongly of gasoline? Is the oil level increasing or changing noticeably?

If so, and you are finding fuel or fuel-laden oil in the airbox, one of the seals/o-rings inside the carb, or a leaking petcock in the fuel tank may be the culprit, rather than rings, at least for that symptom.

That would also potentially explain the engine starving for fuel and stalling if that is what is happening

[DaBlue1]

Originally Posted by hobosmeller

....last but not least, after trying to get the bike to run today, a small pool of oil collected at the bottom of the hose that connects the air box to the oil sump. it was very thin and smelled like gas.

The other way that gas can get into the airbox is by reversion (a worse case scenario).
Reversion is the flow of the air fuel mixture out of the cylinder and into back into the intake manifold. Reversion happens even on a stock engine because the piston is moving up the cylinder before the intake valve closes. This is usually a sign of a needed valve adjustment or the timing is off. Ever considered swapping the CDI to see if it resolves the problem? It's an easy thing to try. An 19 year old CDI can be bad.

https://www.youtube.com/watch?v=VLLZavItixY

[hobosmeller]

Originally Posted by Motofool

That is all that knob-cable mechanism does: to keep the butterfly valves cracked open to the point where a stable .

you and everyone has been slowly putting my bike back into running condition, I can never thank any of you enough
but I adjusted it and it seems to helped but after too much adjustment it would bog down so I would turn it back but the idle still is too high

Originally Posted by PHMCS

berryman B12 Chemtool <---this stuff is no joke, I poured like half of an ounce into a 2 gallon container of fresh gas and it might just be placebo but the bike is running better! (not right, but better!)

The battery tray mod will save a ton of hassle, it was the first mod I made to mine and it has saved me much swearing.
did this and it has helped a lot! although I took the airbox out completely lol

Since your tank was rusted, have to made sure the petcock is working properly? (not clogged, not leaking into your crankcase)
was something i had to replace when I first got the bike, I got it from a bike junkyard kind of thing, it was in better condition than my old one
In regards to the oil/gas in the airbox, was it a substantial amount?
just a little puddle, I've been told it was a normal amount
Have you had a leak down or compression test done on the engine?
i have not unfortunately
Ah forgot in previous post:
If you open your oil cap does it smell strongly of gasoline? Is the oil level increasing or changing noticeably?
not that I've noticed, but it does smell a little

If so, and you are finding fuel or fuel-laden oil in the airbox, one of the seals/o-rings inside the carb, or a leaking petcock in the fuel tank may be the culprit, rather than rings, at least for that symptom.
which o ring should I be looking for if this is the case?
That would also potentially explain the engine starving for fuel and stalling if that is what is happening

Originally Posted by DaBlue1

The other way that gas can get into the airbox is by reversion (a worse case scenario).
Reversion is the flow of the air fuel mixture out of the cylinder and into back into the intake manifold. Reversion happens even on a stock engine because the piston is moving up the cylinder before the intake valve closes. This is usually a sign of a needed valve adjustment or the timing is off. Ever considered swapping the CDI to see if it resolves the problem? It's an easy thing to try. An 19 year old CDI can be bad.

https://www.youtube.com/watch?v=VLLZavItixY

thank you I will try but I heard/read the CDIs are quite hardy and usually last for a very long time but then again 19s is a long time lol

[hobosmeller]

thank you to everyone on here who has commented, I really appreciate it and will be forever grateful.

a small update:

the gas in my inline fuel filter turned orange, probably because it's almost 3 weeks old and my tank is the rustiest tank on this forum. I also drained out 1 float bowl but couldn't reach the other. I poured in new gas mixed with some Berryman and to my surprise, (even with a bad battery) she started right up like everything was normal. the idle was at 3k though and no fuel was coming out to fill the fuel filter so I'm guessing it didn't reach the other float bowl. she ran for a good five minutes before I shut her off because the exhaust on the empty float bowl side was popping.

eventually the fuel started to fill the filter and then the bike started to run rough again, could there be something wrong with that one carb that is causing the bike to run bad?
also when I turned on the bike the first time, it was on it's center stand.
another thing, the idle was jumping up from 2.5k to around 5k on it's own with nothing being moved and choke off, then it would come down for a little bit then jump up again. there is a lot of oil on my exhaust header causing a good amount of smoke to build in which I turned off the bike but it wouldn't turn on again.

there are no leaks and everything seems like it should be good but it just won't run right...

ps: last time I took the carbs out, I set the idle screw 2.5 turns out and messed with the balancing screw. I opened up the butterflies more and used sunlight as a measurement to "balance" them.

[DaBlue1]

Originally Posted by hobosmeller

....eventually the fuel started to fill the filter and then the bike started to run rough again, could there be something wrong with that one carb that is causing the bike to run bad?

Did you ever fix the orientation of your fuel line?

[hobosmeller]

Originally Posted by DaBlue1

Did you ever fix the orientation of your fuel line?

no sir I haven't

I'm gonna order the filter with the 90* bend tomorrow from eBay
(posted above)

this bike is so close to running, I've been having dreams of riding it haha

[DaBlue1]

Originally Posted by hobosmeller

.....I'm gonna order the filter with the 90* bend tomorrow from eBay
(posted above)

this bike is so close to running, I've been having dreams of riding it haha

In the meantime, why not just make your hose shorter?

[Ninjinsky]

Originally Posted by DaBlue1

In the meantime, why not just make your hose shorter?

Both of them in fact and running the hose against the hot water pipe looks like a good way to get a vapour lock

[hobosmeller]

I want to keep fixing it up but my car needs repairs, so I think I'm just gonna have to sale it.