pulling the carbs again

[Bob KellyIII]

well, I went out and started the 250 Ninja several times now and it hasn't gotten any better... so I decided to pull the carbs and clean them up myself to try to get this little beast running good again...
one cylinder drops out at idle and all the way up through mid range then it kicks in.... so I'm taking it apart.
I decided to do that outside on our patio this time sense my shop is so small
and in about 3 hrs working time I have the carbs in my hand. that is a new record for me last time it took me days, but I knew what had to be done to get the fairings off and the carbs off this time so that is good ...it wasn't near as frustrating this time... and having it on the Patio is alot better.... i just hope it doesn't rain ! LOL ( you KNOW it WILL ! ) there is still patches of snow on the ground here from the 3" we had last week !
but spring is trying to get here !
.......
I've not opened up the carbs yet but I am sure I will find clogged jets even though I put Sta-Bul 360 in the tank before I parked it for the winter !
....I do have a in line filter between the gas tank and the carbs and I would have thought that would have cured that but evidently not.... it has set for 2 years sense I got it running again with fuel in it because there is no way to turn off the gas and then run it till it dies ...the petcock is hidden under the fairing unfortunately. so I am not surprised that I have to do this again
I am seriously thinking about drilling a hole in the fairing so I can turn off the fuel and then run the carbs dry so they won't clog up so bad !
not real sure that the petcock has an OFF position to be honest. there is on and PRI but that is all I saw in passing.... on is with the vacuum portside and PRI is a pass through bypassing the vacuum port..... I'm fairly sure.
we'll see, I'll look closer at it later.

Bob.....

[ducatiman]

best o' luck, Bob

[Bob KellyIII]

Thanks ! had the carbs out and cleaned and back in already
I found a few drops of gunk in the bottom of the fuel bowls on each side
and the pilot jet completely plugged on the right and pilot jut partially plugged on the left but I could see a tiny bit of light coming through it....
.......
Hay Gordon do you know if the pilot jets are the same size compared to each other on this 2012 ninja.... sense the initial settings are different with the carbs they may not be the same size... and mine are not... there is a really tiny difference in the diameter of the pilot hole.... the tip goes in on one pilot jet
but not the sarations on the tool.... but on the other pilot jet the whole tool gord through easily. ( tip and sarations)
I hit the carbs with carb cleaner and put them back together !!!

I didn't figure they were all that dirty ! Gordon had just worked his magic on them 2 years ago. and they still look fantastic inside and out.... and they would have worked fine if I had taken proper care of this bike...but I didn't...totally my fault ! ....
the problem is that pilot jet is so small that it will catch any tiny particles that come in with the gas.... and I think STA-BUL 360 has a tendency to make particles in the gasoline.... because My triumph has to have the pilot jets cleaned each time I start it now and Stabul 360 is the only thing that has changed !

anyway she's going back together now... should have her running by this evening we'll see !


Bob......

[ducatiman]

both identical #38 pilot jets

[Bob KellyIII]

ahh thank you ! that helps alot !
I got it back together and fired it up it started easy on both cylinders but
it has a huge flatspot at about 5k rpm.... after I got it going before it had a big flat spot at the same place but I messed with it and got it almost completely eliminated..... but it is back with a vengance now.... that flat spot is a cylinder dropping ( not fireing) if I turn on the choke lever that dead cylinder picks up and will take the RPM.... so for some reason it is running lean at mid range to full throttle.... Idle it is fine now I left it at the factory settings for the pilot air screw and it works so I'm not messing with it ! LOL
I did pull both main jets and make sure they were clean , they were.
but I did not disassemble the carbs any further thinking all it was was plugged pilot jets...... I should'a known... nothing is easy on a Ninja ! LOL
so I will pull the carbs off again I think I will return everything to factory condition and see how it runs then... if the big flat spot persists I will probably change the mainjet on that side for a slightly bigger one like .5 bigger.... i believe it is the Right cylinder that is giving me fits it keeps dropping out it will pick it back up at idle or from 8k up to 12k RPM but from 4k to 6~7k it stops firing
....

last week we has SNOW....today it is over 80degrees and sunshine.
crazy weather at 4000'asl ! LOL
....
i'm headed back out to pull the carbs off again and this time I will go through them completely.
....
Bob...

[Bob KellyIII]

Hay Gordon !
95 is stock main jet size right ?
both carbs have 95's.... I am thinking that changing them to 100's may well cure my problem
....
I do know that because of the EPA they leaned out bikes so lean they are lucky to run at all.... and at my altitude maybe it's reacting worse than at sea level
....
going up in altitude usually makes it Richer though..not leaner but the symptions I'm getting is it's too lean not too rich...so I am confused and trying to figure out why it's screwing up on me....
I think larger main jets is the simplest next step and just see if it likes it better
I had put 2 tiny washers under the jet needle before when I was fiddling with it trying to get it to get past the flat spot so I took those out just now and we are totally back to stock.
I think I'll try the next size larger for the main jets and then do a color check on the plugs if it doesn't have a flat spot any more( which I hope it won't!)
....
I bet you larger MJ's will cure the problem ! i have a feeling !
....
Bob.

[ducatiman]

95 mains? Where you getting this info from? 98 comes from the factory as stock size.

[Bob KellyIII]

that is interesting ! my carbs have 95 mains in them not 98's
.... so I assume that is the problem !
ok at least I found Something wrong....
I will double check and triple check because those numbers are very hard to see even with magnifying glasses on !, but I am sure their both 95's
.....
I bought a bunch of jets for the XR650L and I searched till I found them in the shop last night.... so hopefully I have some 98's on hand...we'll see !
thanks Gordon
... Bob
....I should double check the pilot jet sizes to.... while I have the carbs out.
the P.O. may have changed this stuff ya never know !

[Bob KellyIII]

Ok... I just re affirmed that the main jets are both 95's and the
pilot jets are #40's
....
seeing that they are supposed to be #98's for the main jets and #38's for the pilot jets..... I find that really weird !
....
he may have had to go to #40's just to get it to idle correctly at this altitude but I can't understand that logic because as you go up in altitude the standard sea level settings get RICHER not leaner...
so I cannot understand the P.O.'s logic at all on these carbs ! leaner mains and richer pilots makes no sense at all to me ! even for racing ! which I think this guy was trying his darndest to be !
so I will be forced to buy the correct mains and pilots jets before I put this thing back together again...
nearest Kawasaki shop/dealer is 71 miles away..... UGH !
but I have to go down there next week anyway so hopefully I can pick them up then !
....
Bob...

[ducatiman]

I'd urge you to review our PM's from last year. You sent the carb set back for a review AND some jetting changes. I believe (upon reading a PM) that you insisted on 95 mains and 40 pilots, with shimmed needles...that I did. I'll find the PM/date if necessary.

[ducatiman]

A quote from your PM.....April 30, 2023

"95 mains , 2 shims each.... that should do it !
I'm happy with that !
Bob......"

[Bob KellyIII]

your absolutely right ! about 30 min ago I found all my old jets !
so somewhere along the line I DID IT ! and the logic I was using at the time was it doesn't run right with stock jets so lets try other ones....
.... sense I have the stock jets now... I will put them back in and put the carbs back on and see if it runs properly.
it probably won't but I know the carbs are proper , so it must be something else other than the carbs....
I am thinking maybe the air bypass valve on the side of the carb.... I did notice
it back firing when I throttled down..... and I don't remember it doing that before....
if the diaphragm on the side in that bypass air valve was blown it might give a big flat spot in the RPM's......
Getting old and forgetful in the middle of a bike teardown is not a good thing
but that is all I can contribute this fiasco to.... me getting dumber ! ACK !
....
it wasn't the P.O. it was me stopping half way through testing what the different jets responded like.... and then forgetting about it putting the fairings back on to get it out of the shop and then wondering why it doesn't run right.....
Ugh ! life's a bitch when your an idiot ! LOL

but I Now know where I'm at ! lets see if I can make this ninja Sing again !

Bob.....

[Bob KellyIII]

LOL....
I put the carbs back to stock ...stock main jets, stock pilot jets
hooked it all back up hit the starter and it fired right up ! both cylinders firing
like it should be....
reved it up.... no hesitation at all, gained RPM like it should..... NO Flat spot!
....
reved it a few more times and it seams to be back to her old self !
....
I still have the water tank dangling and the seat off and I want to ride it without the fairings on it before I put them back on....
.....
the only thing I can figure was the problems I was having before was from a dirty carb.... and my mind was stuck on the symptons ! but I had Gordon clean the carbs last year and I've had Sta-bul 360 in the fuel sense then even though it sat for a full year...... once I put the carbs back to stock it seems to be running like a champ !
....
I fully expected it to have a huge flat spot at 4k RPM because that is what I was getting last time I had it in stock configuration.....
....but that is not the case.... it is running fantastically now.... at least on the stand !
we'll see what it does under a load and riding it next week
.....
thanks for the help Gordon in reminding me what I did..... memory doesn't serve me well any more....obviously !
.....
IT WORKS !!!!

Bob........

....

[Bob KellyIII]

LOL as with any good fix it job you wait till the next day and try it again...
so that is what I did....
I went out there turned on the choke turned on the key and hit the start button and it made 1 full revolution and fired right up gained RPM because of the choke being on...( it's 70 deg. today so I probably didn't need the choke at all anyway) with the choke on it gained RPM to almost 5k RPMs so I turned off the choke and the idle came back down.... it was idling kind'a slow like 500 to 800 RPMs so I adjusted the idle to around 1200 RPMs sense it was cold at that time it was hesitant on taking throttle but soon got over that and took throttle like a pro..... no flat spots anywhere in the range she is running perfect !
only thing that might be a bit off is the quickness of the throttle but I attribute that to being a cold engine...
I am so relieved ! I haven't taken it out for a ride yet as I don't have licenses on it for this year.... soon I hope.
....
she really is running good probably the best sense I got her
I can't wait to get her out and stretch her legs ! it's been 2 years she's been down ! this bike has always been a fun ride but it's no dirt bike !
and that is what the XR650L is for....
.....
Bob....

[ducatiman]

yahoo....great job BobKellyIII

[Bob KellyIII]

LOL thanks Gordon !
I went out there and decided to just go ahead and put the fairings back on
so she is all ready for a test ride.... I'll run up to the nearest gas station and fill the gas tank, I don't have current licenses on it right now so I'll have to be sneaky LOL
Bob....