I posted this on another forum a few days ago and just copied and pasted it over here. so the timelines are off a tad. LOL


Hi. New guy here. Well I've always told myself i would NEVER buy a new vehicle, and here i let the wife talk me into getting a new ninja last year. And here I am. screwing the warranty after having been told by the dealer that they won't do anything because "the bike is fine and it's normal". I'll just stick to working on my own rigs.



So i'm hoping you guys can help me figure this one out. cuz i'm out of ideas.

2007 Ninja 250, 4,000 miles NO MODS.


about a month ago, it nearly overnight developed this really odd problem that has been getting worse and worse to the point that my wife can duplicate it on command like clockwork.

on a cold start (first time in the morning, or after the bike has sat for a couple hours) when she takes off for the first 1/4-1/2miles, the bike will run fine, but when she is coming to a stop and goes to pull in the clutch lever in, the bike will die. sometimes it takes several attempts to get it to restart. it will do that several times. generally on our "test runs" she can get it to do it at least 2-3x. once you get going though, and the bike gets just a tad warmer, then it won't do it anymore.

and on really cold cold starts, you pull the choke, start the bike, let it warm up, turn the choke off and it dies. then it takes several (up to about 10) tries just to get it started again.

Now the i have personally been able to duplicate the problem. my wife went to the dealer every day for a week while they kept it there to work on it, and every day duplicated the problem with 2 service writers and techs watching. they even got on their own bikes and followed her down the road and watched the bike die. so they obviously saw it happen. one of their own guys was able to make it happen. but only 1x.


the only thing the dealer did was clean the carbs (which they said looked 100% clean, but they just did it anyways), found the atmospheric pressure vent pinched off, so they fixed that and aired up the tires. they called us and told us the bike was fine and wasn't dying anymore. but within 5 minutes of us getting there, the wife duplicated the choke dying and the clutch dying at least 4x.



well today they told us that since their techs can't find a problem and can't duplicate it, that there is nothing with the bike and that they will not work on it anymore.



any ideas where i should start. cuz i've been sitting next to this bike for the last couple hours racking my head with ideas, and i honestly have no idea where to start. i have taken it on test rides to see if i can notice anything that may be unrelated to the clutch that might be killing it, but only does it for the first 1/4-1/2mile after a cold start, and only when pulling in the clutch to coast/stop. clutch/shift is fine. only when you pull the clutch and let it coast or to brake does it die.


Thanks.

Try adjusting the free play on the clutch lever. It may be out of adjustment.

Try adjusting the free play on the clutch lever. It may be out of adjustment.

clutch is adjusted properly.

wondering if your altitude has an affect, what are the rpms when you have choke on? Can you possibly leave the choke on to keep the rpm's around 1.3-1.5k and ride it like that to see if it stops the engine from dying when pulling in the clutch to stop. If it doesnt maybe the bikes not getting the air/fuel it needs...

The only thing else that I can think off is to pull the spark plugs and check there condition and replacethem if required. Also try runing some sea foam cleaner thru the gas tank. If all that checks out good then try looking into the nuetral kill switch. I hope this helps.

Just had a thought: before doing what's below, completely drain and re-fill the gas tank with fresh gas, and drain the float bowls into a clean cup. Inspect the cup for signs of particulates. Double check air filter and potential for airbox obstruction. To rule out tank vacuum issue, ride with the gas cap loose one day.

Just had another thought: before doing what's below, make sure the choke cable is adjusted so that when the lever is all the way forward (no choke) there is a little bit of slack in the cable.

--------------
You need to pull the carbs again, and do it yourself this time. The FAQ at Ninja250.org should be able to help in this regard. Here's what you need to check:

Pilot jets (the sunken-in ones): Make sure you can see through the side holes, spray some carb cleaner through the body orifice, follow with COPPER wire and more carb cleaner

Floats: Set the float height to 17mm, insure the piston moves freely and that the seats are clean

Now, I don't expect those to be a problem. While you're in there, throw a #4 washer underneath the needles.

Next, close the carbs back up and pull the EPA plugs that cover the mixture screws. Easiest way to do this is to put the carbs in a vice on your drill press, drill a 1/8" hole no more than 3/16" deep and thread in a self-tapping machine screw. Then grab the screw with some vice grips and pull the plug out.

Once you have the caps off, turn the mixture screws all the way in -- count how many turns. If it was less than 2.75 or more than 4, reset set them 2.75. Otherwise put them back where they were.

Reassemble. Pay close attention that you get a good seal against the airbox. It's a bitch.

Wes

my first thought was the gas as well - since you said she hadn't ridden in a year because of the baby, how was it wintered? did you store it with gas in it? have you filled up lately? perhaps completely draining the tank and putting fresh gas in will help fix the problem?

wondering if your altitude has an affect, what are the rpms when you have choke on? Can you possibly leave the choke on to keep the rpm's around 1.3-1.5k and ride it like that to see if it stops the engine from dying when pulling in the clutch to stop. If it doesnt maybe the bikes not getting the air/fuel it needs...

tried that already too, and doesn't matter. even with choke on, it will intermittently die. sometimes it dies just by turning the choke off after letting it warm up, and then it won't restart. so it dies either way.

The only thing else that I can think off is to pull the spark plugs and check there condition and replacethem if required. Also try runing some sea foam cleaner thru the gas tank. If all that checks out good then try looking into the nuetral kill switch. I hope this helps.

have to check the plugs yet. already ran seafoam through (i don't use anything else. but seafoam rocks.) and ran the hell out of the bike just to make sure it didn't need to just wake up.

i was going to try and temporarily bypass/disable the clutch switch at the clutch lever, and the kickstand switch to see if that would change anything. but i don't have the service manual yet, and without a wiring diagram i don't wanna go messing with that.

Just had a thought: before doing what's below, completely drain and re-fill the gas tank with fresh gas, and drain the float bowls into a clean cup. Inspect the cup for signs of particulates. Double check air filter and potential for airbox obstruction. To rule out tank vacuum issue, ride with the gas cap loose one day.

Just had another thought: before doing what's below, make sure the choke cable is adjusted so that when the lever is all the way forward (no choke) there is a little bit of slack in the cable.

--------------
You need to pull the carbs again, and do it yourself this time. The FAQ at Ninja250.org should be able to help in this regard. Here's what you need to check:

Pilot jets (the sunken-in ones): Make sure you can see through the side holes, spray some carb cleaner through the body orifice, follow with COPPER wire and more carb cleaner

Floats: Set the float height to 17mm, insure the piston moves freely and that the seats are clean

Now, I don't expect those to be a problem. While you're in there, throw a #4 washer underneath the needles.

Next, close the carbs back up and pull the EPA plugs that cover the mixture screws. Easiest way to do this is to put the carbs in a vice on your drill press, drill a 1/8" hole no more than 3/16" deep and thread in a self-tapping machine screw. Then grab the screw with some vice grips and pull the plug out.

Once you have the caps off, turn the mixture screws all the way in -- count how many turns. If it was less than 2.75 or more than 4, reset set them 2.75. Otherwise put them back where they were.

Reassemble. Pay close attention that you get a good seal against the airbox. It's a bitch.

Wes


the bike gets a full fresh tank of gas roughly every 2-3 days.

i didn't check the bowls or the carbs yet myself this year since as i mentioned, the dealer says they pulled the carbs apart and cleaned them (even though i told them that wasn't the problem, and since it's still doing exactly what it was before, i guess i was right). so i would assume that for now it's clean.

i did pull that little joke of a fuel filter out of the tube going to the carb yesterday, and it was clean.

air filter seems to be good.

already tried riding with the gas cap open. no change. still dies.

i checked the choke slide and cable couple days ago. seemed to be adjusted perfectly. with just a hair of slack in the cable, and a small gap before the bracket engages the needle to start sliding it.

the plug on the air/fuel mixture screw is already removed. the dealer said they removed it and turned the mixture up just a hair richer because they said it was running to lean. (which i believe to be true after some extensive research yesterday, i discovered that excessive blueing of pipes is caused by lean condition, and gold is running normal-rich. well her headers are completely blue all the way down past the lower bends under the bike.



the part that is throwing me off is the fact that the problem started practically overnight without anything having been done to the bike at all. one day it was fine, and the next day it started stalling and getting progressively worse.



for some reason i keep thinking that it's either an intermittent electrical issue in the clutch/kickstand circuit, and that's why it only does it with the clutch pulled. but if it was an electrical issue, then i would assume it would do it all the time, not just on cold starts.

i also keep thinking that it's almost acting as though it was running just barely rich enough that it's actually flooding it until it gets up to temp. but not real sure about that either.

When I get home I will take a pick of the section in the service manual and post it for you here.

Having followed your original thread, and now this duplicate, something finally clicked in my head....

It's dying when she pulls in the clutch, which in and of itself, should not kill the engine, since all it's doing is taking the load off. So I got to thinking - what else is happening at the same time?

Is it when she pulls in the clutch to up-shift that it dies? When she pulls it in to down-shift, or when she pulls it in to idle at an intersection?

If it's while pulling it in to idle, it may be a simple matter of idle adjustment. The quick way to check this is to have her try keeping a small amount of throttle open when she stops and idles. If that fixes it, then it's just a matter of turning the idle adjust screw (which does the same thing as giving it a little bit of throttle.

On my Virago, if I adjust my idle setting to idle at 1,100 rpm after the bike's been warmed up 10 minutes or so, it will do great, and idle smooth - unless I ride for more than an hour on a hot day, and then it will die when I come to an intersection and pull in the clutch. It's not dying because the clutch got pulled in though, it's dying because the idle adjust isn't proper for those conditions. After the engine is hot (or fully warmed, or whatever) if I then adjust it for an 1,100 rpm idle, it will be fine, but on shorter rides, it will be idling around 2K. I assume it's just an issue of jet expansion/contraction due to heating.

Having followed your original thread, and now this duplicate, something finally clicked in my head....

It's dying when she pulls in the clutch, which in and of itself, should not kill the engine, since all it's doing is taking the load off. So I got to thinking - what else is happening at the same time?

Is it when she pulls in the clutch to up-shift that it dies? When she pulls it in to down-shift, or when she pulls it in to idle at an intersection?

If it's while pulling it in to idle, it may be a simple matter of idle adjustment. The quick way to check this is to have her try keeping a small amount of throttle open when she stops and idles. If that fixes it, then it's just a matter of turning the idle adjust screw (which does the same thing as giving it a little bit of throttle.

On my Virago, if I adjust my idle setting to idle at 1,100 rpm after the bike's been warmed up 10 minutes or so, it will do great, and idle smooth - unless I ride for more than an hour on a hot day, and then it will die when I come to an intersection and pull in the clutch. It's not dying because the clutch got pulled in though, it's dying because the idle adjust isn't proper for those conditions. After the engine is hot (or fully warmed, or whatever) if I then adjust it for an 1,100 rpm idle, it will be fine, but on shorter rides, it will be idling around 2K. I assume it's just an issue of jet expansion/contraction due to heating.



sounds like a somewhat decent explanation. has nothing to do with "quick" clutch pulls. upshift, downshift, etc... is fine. it only happens when you hold the clutch for extended time.

"generally" you only hold the clutch for extended time is when you are slowing to come to a stop. so for the longest time we would word it "stalls when coming to a stop".

then while diagnosing it, i asked her if it also does it just riding, so she tried it, and discovered that she can often times duplicate the stalling issue by simply pulling in the clutch (no throttle) no matter what gear, mph, or RPM.


i did adjust the Idle up yesterday just a tad bit, but as you said i noticed that if it wasn't "fully" warmed up yet, then it would be where i adjusted it to. but then after riding it, it would be a tad off from where i set it, etc..etc..etc..


well from reading this forum, it seems that most of you guys seem to be happy with your little 250's. so hopefully i can figure out this problem soon, so the wife can ride it a little safer and enjoy it better. cuz the last few days i've been getting very upset that we went to buy a bike and bought a toy instead. i was starting to wonder if "that's what i get for buying a toy".


oh and no more new bikes. no point in paying extra for warranty, service plans, etc... when i end up having to wrench on it myself like i told the wife would happen. oh well...........live and learn right.

sounds to me like the pilot jet is clogged or the idle adjustment is so out of whack, after it warms up, it's not getting enough gas.

if you think it an electrical issue, bypass the clutch switch as you have planned.

and personally, if it's under warranty, I'd be back at the dealer to make them fix the problem. mention something about "lemon law" and see if they don't help you a bit more... or find another dealer.

I'm with kkim thinking it's a pilot circuit problem.

I never trust dealers to fully/completely clean carburetors.

It sounds to me like the pilot mixture is too lean. This can happen with poor adjustment (and they are all poorly adjusted from the factory), extreme mild clogging in the pilot jet (slow jet), or a combination of both.

I can virtually guarantee it's not an electrical problem of any sort. That includes plugs. :)

Wes

sounds to me like the pilot jet is clogged or the idle adjustment is so out of whack, after it warms up, it's not getting enough gas.
.


the problem is NOT after it warms up. it's on cold start (regardless if first start of the day, or after a couple hours of sitting). after the first 1/2-1mile, it seems to be fine.

are you leaving the choke on for that first 1/2-1 mile?

what rpm does your bike idle at after it's fully warmed up?

scorpio_vette: Recall that you need more fuel in the small-throttle-opening range when the engine is cold than when it is hot. This is because the fuel can condensate and cool the intake tract, head, and cylinder wall before the spark tries to ignite it. That is why we have a fuel enrichment circut, and why the engine is more sensitive to pilot circuit tuning when it is cold.

Wes

are you leaving the choke on for that first 1/2-1 mile?

what rpm does ytour bike idle at after it's fully warmed up?


no we are not. i did try it for "testing purposes", and it still died.


no please bare with me, and don't take this as in me trying to argue. i'm just trying to learn and understand and look at it from all angles.


when we first purchased the bike and rode it last year, we only had to use the choke for approximately 30seconds-1minute, and the bike was ready to roll. never had any issues. this year it started fine after sitting over winter (winterized), and started/ran fine with only having to choke it for less than 1minute, and it was ready to go. this whole dying issue started practically over night, and was only occasional for the first couple of days, and then over a matter of days got so bad that now it does it on every cold start guaranteed like clockwork.

so how would the bike go from being fine one day, to suddenly have a bad jet, etc..... over night???



now i will be pulling out the carbs here very soon (as soon as time permits. a little harder now that i gotta watch our little 5month old all day. LOL) just to make sure. does anybody have a writeup specific to these little ninja carbs, just to make sure i don't overlook anything???




sorry for all these questions and back and forth. i know it really sucks, but i just seem to be really stuck on what and/or how the bike could have went to crap overnight. usually from my experience, when parts go bad over night, they have to be functional/moving parts, such as fuel injectors, electrical, water pumps, etc... but a carb jet is nothing more than a hollow "tube" of varies sizing (depending on the jetting) correct??? so for a jet to go bad overnight, you'd have to get something stuck in one, or get some really really really really messed up gas. correct???



the RPM was originally set to 1,200-1,300 (i think), and always held steady after warmup. yesterday night i turned it to approximately 1,500 after warmup to see if that would make a difference, but the wife got home today and set the bike still died on her.

After it is warmed up it works fine, no issues?

scorpio,

I've not taken your replies as arguments... in fact your last post really cleared up a lot of things. troubleshooting over the internet is not an easy task, so if I ask questions that sound dumb or give recommendations that are flat out wrong, it's because of not being there to witness firsthand.

it does sound like you have some dirt stuck in in the carbs. Taking them apart and cleaning them would be a good idea at this point.

do you happen to know what the mixture screws are set at now?

do you have a service manual?

http://faq.ninja250.org/wiki/How_do_I_work_on_the_carbs%3F

After it is warmed up it works fine, no issues?

Alex, as I understand it, the problem occurs after the bike is fully warmed and when the clutch is pulled in, it dies.

is that correct, scorpio?

This has actually happened to me a couple of times right after I got my bike. What my dealer found was that the setscrew from the idle was messed up. It would move on it's own just from regular engine vibration. That was throwing my idle completely off and making a cold start dang near impossible. It would die on my constantly, especially when pulling the clutch in. Not saying it'll fix it, but check your idle screw just to be sure that it's not only in the right position, but not moving without your permission. That's all I can think of, and it probably won't help, but that's what I get for being a sad excuse for a mechanic! :D Hope it helps and if not that you figure out your problem! :thumbup:

Alex, as I understand it, the problem occurs after the bike is fully warmed and when the clutch is pulled in, it dies.

is that correct, scorpio?

no. it ONLY does it on cold starts (regardless if it's the first start of the day, or after the bike has been sitting a couple hours). it does it roughly within the first 1/2-1mile after cold start.

just for testing, i even had the wife start the bike, and let it warm up for 5minutes exactly (i timed it with a watch), and then take it for a test ride. it still died. but after the first 1/2-1mile AFTER A COLD START, then it works just fine.


that is why we can duplicate so perfectly on command. all we have to do is wait for the bike to cool down, and we can do it every single time.




unfortunately i will not be able to work on the bike for a while now as i herniated a disc in my neck last night and have very limited mobility right now. so i guess i have alot of time to do some more research and get ready to work on the bike once i get better. LOL


i currently do not have a service manual, but will be ordering the set here shortly.

Ouch! Bad news on the hernia! Hope you feel better soon. :thumbup:

just for testing, i even had the wife start the bike, and let it warm up for 5minutes exactly (i timed it with a watch), and then take it for a test ride. it still died. but after the first 1/2-1mile AFTER A COLD START, then it works just fine.

You know, this is a classic pilot circuit issue. You really need to look at your carbs. If you had the EPA caps off, a half twist would probably fix it right up.

Wes

You know, this is a classic pilot circuit issue. You really need to look at your carbs. If you had the EPA caps off, a half twist would probably fix it right up.

Wes

well since i can't move for a while, i was able to get my hands on the service manual last night. so i got some good reading material to pass the time. LOL


the EPA cap(s) are the little plugs that go over the air/fuel mixture screws on the bottom of the carbs right??? the dealer claimed that they removed them and turned the air/fuel mixture a tad bit richer. but i'll check that too when i end up pulling the carbs after i get better.

ok so i read the service manual today, and so far only 1 thing seemed to really catch my attention.

"coasting enricher system"


now i believe i understand how the "choke" or enricher circuit on the 250 works, BUT

when i tried to google "coasting enricher system", i seemed to find some information that a "coasting enricher system" actually supplies fuel at certain times while the clutch is pulled and coasting due to differences in vacuum or something. (sorry i read way to fricking much about bike carbs and engines again today that i'm at the point of a headache and very very confused. so i have to let this all sink in for a day and then go and re-read it all again. LOL)



anyways, does the enricher system on the 250 have some type of "auto supply" or something that might not be working on my bike when it's cold, and therefore not keeping it running when holding the clutch???


or do our bikes ONLY use the enricher system when the "choke lever" is pulled???

http://faq.ninja250.org/wiki/How_a_carburetor_works:_Carbs_explained#COASTING_ENRICHER_-_Feeding_a_Closed_Mouth

hope this helps.

http://faq.ninja250.org/wiki/How_a_carburetor_works:_Carbs_explained#COASTING_ENRICHER_-_Feeding_a_Closed_Mouth

hope this helps.

yeah that is one of the many many things i was reading today.


but i'm somewhat confused. based on what i'm reading, that seems to sound like exactly what might be wrong with our bike. when pulling in the clutch and coasting, it dies. and that's what this:

COASTING ENRICHER - Feeding a Closed Mouth
You're blasting down the road and you see a hairpin coming up, so you close the throttle. This closes the butterfly valve. You and your 400 lb. baby (the bike, not the other love of your life), are still rolling with inertia, keeping the engine revs high. Now it can't get the mixture it's trying to suck in because the butterfly valve is closed, blocking the air flow.
http://faq.ninja250.org/images/thumb/c/c1/Jim_carb_17.jpg/150px-Jim_carb_17.jpg
http://faq.ninja250.org/images/e/e3/Jim_carb_16.jpg

To compensate for this there's an air jet in the lower diaphragm chamber that transfers ambient pressure to one side of the coasting enricher's spring-loaded cut off valve. The excess vacuum in front of the butterfly valve is transferred to a drilling that leads to the other side of the cut off valve. This sucks it open, allowing the pilot jet to feed more fuel to the engine, preventing an overly lean condition. (Pop. Pop. Pop.)

sounds like it controls. so could it be possible that something with this part, circuit or whatever you want to call it might be bad???

any explanation why it only does it on COLD STARTS, but after it warms up it's fine???

maybe it's only partially blocked (some dirt in the enrichener drilling)? On cold starts, you need more fuel than a warm start.

maybe it's only partially blocked (some dirt in the enrichener drilling)? On cold starts, you need more fuel than a warm start.


any suggestions on how to make sure that i 100% "bore" out all the ports, jets and passages??? obviously i don't want to use anything like wire or metalic so i don't scratch anything and cause damage.
i was thinking something like fishing line, or guitar string.


anybody have some recommendations or experience on what would work the best to make sure that they are 100% "bored" out and clean.

those small passages are a real PITA. When I clean out carbs, I usually soak them in a carb cleaning bath, then use compressed air with a rubber tipped nozzle to blow the passages clean from the opposite direction that the flow normally occurs. some spray carb cleaner might work, depending on what is blocking the passage. watch out... any carb cleaning liquid is nasty, so use a lot of rags to catch the flying droplets produced from blowing with compressed air.

sometimes you need to resort to pieces of wire to clean out the bore, though.

You can use COPPER wire on those small passages. The copper is softer than the brass and the aluminium and will not damage it.

I don't think your problem is with the coasting enrichener, normally when it's not working right you get lean-miss backfires. That said, it wouldn't hurt to look at it. It's the snail-shaped thing on the left side of the carbs.

But make sure you turn in, count, and turn out your mixture screw settings. Even if the dealer gave them a twist, they're likely to be wrong. They're almost always set too lean and unequal from the factory.

Also make sure you take the pilot jet right out of the carb. And check your float height!

Wes

Also make sure you take the pilot jet right out of the carb.

Wes

i'm assuming you mean i should make sure i check the pilot jet, or do you mean something else??? your wording is confusing me a bit. sorry.

I believe he is saying to unscrew the pilot jet from the carb when you clean the parts instead of leaving them in the carb when cleaning.

kkim: Yes, thanks for the clarification. Many people seem to think leaving that jet in and soaking the carb in cleaner will get it clean. It won't.

Wes

kkim and wes seem to have this pretty well diagnosed, but my first thought was a dirty or (partially) blocked jet too. My experience with smaller bore carbuerated engines is that they are very sensitive to cold weather, so essentially even a minor carb. problem would be exacerbated by a cold start.

Just out of curiousity, when you wife pulls in the clutch when coming to a stop, has she tried blipping the throttle? Or does she just let the engine rev down to idle? Does the blipping keep the engine alive while its still warming up? This is why I like to downshift when I come to stops as opposed to just coasting in with the clutch in. Also, you don't have to completely take off the choke before you start riding. If I am in a hurry I will leave the choke maybe 1/4 on when I take off, and a couple minutes later switch it off while I'm on the road. If you could upload a video of this it would be a zillion times easier to diagnose lol.

Just out of curiousity, when you wife pulls in the clutch when coming to a stop, has she tried blipping the throttle? Or does she just let the engine rev down to idle? Does the blipping keep the engine alive while its still warming up?
yes she has tried holding the throttle, and believes that the couples times that she tried that it seemed to work, but she only tried it a couple times.


Also, you don't have to completely take off the choke before you start riding. If I am in a hurry I will leave the choke maybe 1/4 on when I take off, and a couple minutes later switch it off while I'm on the road.

as i mentioned earlier, it has died BOTH with and without choke. that's one of the things that keeps seeming to confuse me, because i would figure that if it did NOT die with the choke, that it would make more sense that it was a fuel delivery issue since the choke would be supplying it. but since it also dies with the choke on, that just doesn't make sense to me.

then again it sometimes will also die when you turn the choke off. like instantly. almost like the choke is a kill switch.







anyways, for right now, i think i'm going to wait until my neck is healed well enough for me to work again, then i'm going to pull the carbs out, take them apart, clean them, adjust them, balance them, etc...etc..etc.. and then report back. and if it still does it after that, then we can keep tossing around more ideas. LOL


thanks for all your help guys. now i just hope it doesn't take to long for me to heal up. doc says up to 8 weeks. and that's the GOOD SCENARIO. if it gets worse, and i have to get an MRI, then that means there is a good chance that i'll need surgery. man i'm to young at 27 to need neck surgery. and here i always thought i'd die on my bike, not in the bedroom. LOL

i always thought i'd die on my bike, not in the bedroom. LOL

I've always hoped I'd die in the bedroom.

Sounds like you guys are narrowing it down.. Hope you get better and you get your bike fixed. Interesting issue though.

oh one more question regarding this. i'll try to explain it as best as possible.



oh my bike (04 suzuki volusia) which uses an actual choke instead of an enricher, it raises the RPM with the choke applied. now if i set the choke and take off riding, the bike will continue running a higher than normal RPM whenever i'm not on the throttle.

so until i turn off the choke, the bike will have high RPM.



but the couple times that i tried running the wifes ninja, i noticed that when i start the bike and turn the choke (fuel enricher) on, it will raise the RPM. but when i take off riding, and then let off the throttle and hold the clutch (basically come to a stop), the bike will be running at the normal rpm speed or below.

why doesn't the ninja RPM stay running high if the "choke" (enricher) is still on???

well i took the carbs completely apart and inspected everything as detailed as i could and cleaned everything as detailed as possible and taking my sweet time doing it. also had a buddy over to help.

when i pulled the carbs and opened them, they look like they were brand new with 0 miles on them. but i cleaned the hell out of them anyways.

it's still doing the exact same problem. so right now i'm kinda at the point that i'm trying to ever so slightly adjust the air/fuel mixture at the bottom of the carbs and then taking it for test rides to see if i can notice any difference. unfortunately that's kinda slow progress as i have to keep waiting for the bike to cool all the way.

hopefully tomorrow i will be getting a couple sets of plugs, that way i can
1) check the current plugs to see what they tell me, and
2) replace the plugs, run it, and then pull the new plugs and see what they say.


but otherwise i'm basically back to square one and still am no closer to finding the problem. i'm just bout out of ideas.


i also checked the header pipes temperatures to see how the bike is running, and both header pipes are within less than 5degrees of each other, so the bike is running very smooth and equal on both cylinders.



ideas???

what's the mixture screw settings at? also, did you check the float heights?

what's the mixture screw settings at? also, did you check the float heights?

right now i have them at 2 turns. the previous test run was at 2 1/2 turns.


no i didn't check the float height, as i didn't have anything at the time to check them, BUT (i know i know i'm sorry), i'm fairly confident saying that they are fine, as the bike was running fine before and the carbs had never been opened when the problem started. also, i'm not quite sure if i can see/understand how the float height would be affecting my problem ONLY on cold starts. i would think that float issues would be more constant.

as far as the parts themselves, they were very clean with no wear or other oddities.


if i'm wrong on the float issue, please educate me. :)

i'm fairly confident saying that they are fine, as the bike was running fine before and the carbs had never been opened when the problem started.

just saying you should have checked it when you were in there. :)

did you unscrew the pilot and main jets and blow them out as well as the passages they feed?

at this point, it doesn't sound like a carb related problem, but I have no guess as to what it could be.

any other weird noises that wasn't there before?

no noises, bike runs like a champ otherwise, everything checks out like it's a brand new bike.

ok here is a odd question. lets say the bike is dropped onto the left side (which is has been), and the clutch lever strikes the ground. is there any way that you can think of that would cause damage to the lever that might cause it???

the problem i have with that question though is that if it was a mechanical issue of the lever/switch, then why the hell does it only do it during cold start for the first 1/2 mile or so???

if you don't mind, also read this post on another forum, which sounds somewhat similar to my issue, but i have no idea why the hell it would make sense.
http://www.supermotojunkie.com/showthread.php?t=85944

in the link, he changed the lever, so it must have been something to do with the shape of the lever that was activating the switch.

with your bike, as a test, bypass the clutch switch and see if it improves the issue, but frankly, I can't see how it would make a difference. something to try... you may have a flaky switch. maybe with the choke on, the choke lever/cable is doing something to that switch to keep it engaged?

anybody know how to bypass the clutch switch at the lever??? i was going to do it, but noticed that if i unplug it, the bike won't even crank or anything, and that it has 3 wires going to it. so i didn't wanna jump it until i figure out exactly which wires to jump so i don't short anything.

http://faq.ninja250.org/wiki/Checking_the_clutch_safety_switch

http://faq.ninja250.org/wiki/Cleaning_and_servicing_the_clutch_switch

figures that you'd link to something that i already read somewhere and couldn't remember where the hell i read it. LOL

thanks.

WWWWWHHHHHOOOOOOOOOOOOHHHHHHHHHHOOOOOOOOOOOOO


I believe i have fixed the problem. hope you guys are ready for this, because it's going to be a long read.


1) thank you all for your help, suggestions and continuous diagnostic.

2) i don't remember who it was, but i believe only one or two people tipped on the correct part (possibly in one of my other threads). i will end up elaborating on that in a bit.

3) i'm new to bikes, but from being a car mechanic, i have on WAY TO MANY occasions seen people use "bandaids" to mask the real problem instead of fixing the real problem. I do NOT mean offense to any of you guys, but alot of your suggestions seemed to me like "bandaids" from the start, but not that i have found the problem, hopefully it will help some of you with similar problems down the road instead of having to try and "adjust" it away. some of the things i'm refering to where "turn the idle up", "#4 washer under needle" (might make improvements, but NEVER make mods to fix a problem, unless you know 110% that what you are modding IS IN FACT THE PROBLEM. otherwise, always fix the problem first before modding something), and there were a few other suggestions that were along those lines.

4) I'm EXTREMELY PISSED at the dealer that worked on my bike, and 2 other dealers that i went to. everybody kept screaming "clean the carbs, that's all it can be". the OWNER of the dealer we bought the bikes from said: "my techs have exhausted all their options and couldn't find the problem, so there must not be anything wrong" (well if they exhausted all their options, then why didn't their certified techs find the problem, but a rookie like myself did???). another dealer told me that they get 250's in with the same problem as mine all the time, but have never been able to figure out what the problem is, and that it's "normal" for the 250's (sorry but i'm not buying that. if it doesn't do it from the factory, and it doesn't do it for the first 4,000 miles, then it's NOT ****ING NORMAL)

5) if you don't work on your own vehicles. LEARN how to. nobody will every be as anal about making sure the work is done right as you. plus you won't have to argue with anybody if the vehicle isn't fixed. cuz at that point the only person to blame is you.




anyways..........on to my story.


so after having you guys help me left and right, we obviously didn't come up with anything definitve. so i pulled the carbs with a friend of mine, and went through them with a fine tooth comb. as mentioned before, they looked like brand new. and even after that, the bike still did exactly what it did before.


i tried replacing the clutch switch just for shits and giggles cuz it was easy to get to and only $20, and so that way nobody can tell me it's electrical. well that didn't fix it.

somebody also mentioned maybe the clutch sticking. well it kinda made sense, but kinda not. cuz if the clutch was sticking, then it shouldn't rev as freely as it does. it would have a little bit of a hesitation. it didn't. so i ruled that out.

well i decided to take the maintenance schedule, and do EVERYTHING on the list from top to bottom until i would hopefully find something out of spec or broken.


so i got the valve covers off to do the inspection and/or adjustment of the valves. i decided i would adjust them to the sloppier end of the adjustment range, rather than tighter. 1- so i would make sure the valves are closing, and 2- so i wouldn't have to do them as soon as if i adjusted them to the tighter end.
so i got my feeler gauge out (0.005) and checked the intake valve, and it wouldn't quite fit. so i loosened the lock nut and just barely bumped the adjustment screw, and now it was way to loose. so obviously it wasn't far out of adjustment. anyways, i got all the intake valves set to the same spec. all of the adjustment screws on the intake valves BARELY needed to be bumped to be within spec.

then i moved on to the exhaust valves. i got my feeler gauge (0.006-i think. can't remember), and it wouldn't fit. so i loosened the lock nut, and just BARELY bumped the adjustment screw. still wouldn't fit. bumped the adjustment screw again........still wouldn't fit..........again and again and again and again..................1 FULL TURN +/- a hair. WOW..........the damn exhaust valves were so far out of spec that the exhaust valves weren't closing all the way.


well whoppidy f***ing do...................now it all makes sense. how does a carb work.

air/fuel mixes in carb. intake valve opens (while exhaust valve is closed), and creates a strong vacuum that sucks the mixture from the carb into the cylinder. the intake valve closes. mixture gets ignited and compressed, exhaust valve opens and lets out the power, and then CLOSES AGAIN SO THE CYLINDER CAN CREATE VACUUM WHEN THE INTAKE VALVE OPENS.

well in my case the exhaust valve wouldn't close all the way, and so when the intake would open, the vacuum wouldn't be nearly strong enough to suck everything it needed out of the carbs. on top of that, it can cause the valves to get damaged by burning, the compression isn't nearly as strong because alot of it is wasted out of the open exhaust valve, etc...etc...etc...

starting to see how much can go wrong with the valves not operating properly???


anyways, so i adjusted all the exhaust valves, balanced the carbs, and then let it cool down a couple hours, because as you remember, the problem ONLY occurs on cold stars.


OH MY F***ING GOD..........remember how i said that choke didn't operate properly??? remember how i've said that i could never "adjust" the choke, but it was almost like an on/off switch, and would NEVER choke under 5,000RPM??? remember how i said that when the bike was new it only needed a 30-60second warm up and it was ready to ride???


well the choke now is FULLY ADJUSTABLE. i can actually set the choke as low as 2,000 rpm.

the bike takes between 30-60 seconds of choke (takes longer than that to fully suit up with pants, jacket, helmet and gloves) and is ready to ride.

i can adjust the idle as low as 1,000RPM, and the bike runs just fine. but right now i have it set at roughly 1,500RPM because it feels more "solid".

according to my friend, the bike lifts the front end about 2-3" everytime i shift from 1st-2nd and from 2nd-3rd (i ride very hard and agressive).

now since the bike ONLY would have it's problem on cold start, i would make sure to wait a few hours between tests, and wanted to try it for several days before i called it ok. well so far it's been 2 1/2 days, and about 6 test runs with each one about 2miles long, and the bike HAS NOT DIED ONCE.



so currently my bike is set to 100% STOCK SETTINGS, and functions LIKE NEW.

stock NGK spark plugs gapped to speck
stock pilot, main and needle jet NO MODS
air/fuel mixture set to factory baseline of 2turns
valves adjusted to larger end of spec range (personal preference. as long as it's WITHIN spec, should have same results)
carbs balanced to within 1/8-1/4" of the home made balancing tool, and STAYS balanced up to 8,000RPM (didn't try going above that).
runs fine at stock RPM of 1,300+/- 100, but after testing adjusted it to 1,500 for personal preference.




so as you can see, the bike is running PERFECT with no "adjustments to compensate". all i did was make sure that EVERYTHING was within spec, the air filter was clean, the fuel filter was clean (i did add clear fuel line and clear fuel filter for continuous visual diagnostic), the oil level was at the correct level (i also made sure the drive chain and tire pressure was within spec. LOL)




now i will be going back in within the next week or 100 miles (which comes sooner) to check the air/fuel mixture because it's probably running a tad lean (as it comes from the factory), and then make adjustments accordingly to richen the mixture a bit, at which point, it will probably raise the idle speed a bit and will have to be adjusted down a hair.






so again thanks for all your help, and hopefully this will be of help to one of you guys.

Congatulations on your trouble shooting. Glad to hear you are back in business. We will certainly remember this next time someone has a similar problem.

cool... glad you finally found it. :thumbup:

So glad you finally were able to diagnose the problem. You must be really stoked!! Congrats!!! I know it must've been driving you crazy trying to arrive at a solution.

Do you plan on sharing your findings with your dealer? I would.

congratulations! It's good to hear that you found the problem and were able to remedy it!

So glad you finally were able to diagnose the problem. You must be really stoked!! Congrats!!! I know it must've been driving you crazy trying to arrive at a solution.

Do you plan on sharing your findings with your dealer? I would.


i'll try to keep this short. the bike came with a "service plan" that covers free oil changes, air filters, batteries, etc..etc..etc..etc..

well i knew it came with a free valve adjustment, but i thought it was only for the first time during the break in period.

today i found out that there is another store 1hour away that is part of the store that we bought our bike from. so i called them and asked to talk to the biggest boss there. i talked to him and asked if they would honor that service plan that was purchased with the bike, and he said yes. so i explained the situation to him, and he was extremely pissed. he asked for my name and number, and said he was going to inform the other boss of the situation, and if i wouldn't mind riding up there so i could have a sitdown with the "higher ups" and explain what happened and get this sorted out, but that they would be more than welcome to continue our service for us if i don't want to go back to the original dealer.

he was also upset, because apparently the store we originally went to is supposed to call them if they have problems, or transfer bikes to them if they can't figure it out, but none of them had heard anything in our regards, so he was rather upset at that.

I also could help myself and had to be somewhat of a dick, so i said: "no offense, but i'm a car mechanic. these are the first bikes we've owned, and i don't know anything about bikes. and it sure doesn't make your shops look good when your trained techs get schooled by a rookie like me". at that point he just busted out laughing and said: "yeah we generally don't like to see that happen".

he also informed me that our service plan actually INCLUDES valve adjustments. so in other words....................had the techs done their job and discovered the problem, they would have noticed the valves out of adjustment, and it would have been covered by the $1,000 service plan that was purchased with the bike.

so all the work i just did, and all the tools i bought/build for this project were "sort of" un-necessary. so i'm going to see if they'll re-imburse me something for having to go through that. but for future reference, valve adjustmens are covered under our plan.

anyways, the guy asked me to call them when i decide to come up there for the "sit-down" with the bosses. so i called him back later and told him i'd be riding up there this evening. so he put me on hold to make sure the other bosses would be around, and comes back to inform me that apparently the regional manager got right in his car and drove the 1hour to action powersports to find out what the **** those guys are pulling down there. so he asked me if i could just wait until he got back from there, and they'd call me with what they find out.



at least some people still care about customer service. pretty sad thought that it has to go that far to get decent service.

kind of a moot point now, but i advised valve adjustment for someone with similar problem in a different thread. no one else seemed to concur or acknowledge that option. but, when engine performance is in question, count on:

1.kkim to suggest "another washer under the needles."
and
2.me with "check your valves."

kind of a moot point now, but i advised valve adjustment for someone with similar problem in a different thread. no one else seemed to concur or acknowledge that option. but, when engine performance is in question, count on:

1.kkim to suggest "another washer under the needles."
and
2.me with "check your valves."


it might have been you, i don't remember, but i know somebody had commented in one of my various threads to check into the valves. which i did take into consideration. the reason i didn't do it that day was because of time, tools (had to go buy some decent feeler gauges. i didn't like mine), and i wanted to research every point possible before ripping into the bike, so i could make sure that when i got it back together i had covered all the bases.

if that was you that had mentioned it, then thanks again. you were dead on.

Wow I just read this thread for the first time and I'm glad I waited till now. I woulda been so frustrated with this and it isn't even my bike!

I agree 100 percent about knowing your on bike so you can solve problems like this and don't have to rely on techs who may not really give a poop about your bike.

Glad you got it all worked out and bike is running well. Hope the meeting goes well and you tear it into them...they deserve it
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glad you figured that out, made an interesting read here at work :p