Getting the Ninja going again !

[Bob KellyIII]

I predict You will not find anything wrong with the carbs Gordon. but at this stage everything I know points to the carbs not working correctly.
.... I am thinking that perhaps the Pilot circuit didn't come clean like it should have and something blocked the pilot circuit .... but for that to be true
BOTH carbs would have to have the same problem and the odds of that happening are astronomical ! I have no idea what could be the problem
that is why your getting the chance to check your work for a 2nd time just to see if you missed something... if you do find something out of place or missing Please tell us the truth so we will know what can cause the symptoms that I found trying to get this beast running again.
for me this has been a Mechanical Puzzle, frustrating, but a puzzle non the less. I have never encountered such a problem in all the years of mechanical work.... so this Kawasaki Ninja still is teaching this old man
...
Maybe a mouse has built a nest in the air box and is careful to hide the evidence.. at this stage I will entertain any possibilities ! HAHAHA!
(even that would not do it as it would not run at High RPM, only at low RPM)
......
like I said this one is a really good puzzle !
...
Bob.....

...

[DannoXYZ]

New-gens don't have mid-range lean-spot like pre-gens, so really don't need any carb adjustments in stock form. Both super pig-rich under WOT. Even with full Tyga exhaust, free-flow intake with snorkel removed, I still had to go down 1-size on mains. That's with extra 22% more air-flow than stock (dyno showed 22% power increase with above mods).

Bob, shimming does change mid-range fueling. It basically is tricking carb into thinking air-flow is higher than actual with higher needle position. This increases gap between needle to jet and lets in more petrol. It doesn't affect high-end much because needle stops tapering at tip. Shimming is like taking "Needle Taper" curve and sliding it to left.



So bike runs worse now than before winter storage?
How far off were valve-clearance? How much did you have to adjust?
Do you have table of before & after measurements?

[Bob KellyIII]

Howdy Danno !
I agree with your statements on the shimming of the needle, I probably didn't make myself clear on that.... but like you say it is exactly like putting in a bigger mainjet because you are actually pulling up the needle out of the main jet when you do the shimming...(in effect anyway, the needle sticks into the emulsifer tube not the jet itself but it is close !)
....
the Valves were only slightly off on the exhaust they were just a bit too tight
so I loosened them to get them within tolerance
they were not out far enough to effect the running of the bike, of that I am sure and the change I made would also not have been big enough to change anything... I know that the valves are within tolerance I think I changed the exhaust by a max of .002" or something like that.
the bike only has something like 5,600 miles on it... I do believe those were hard miles however.... there is evidence that he dumped it a few times going too fast in corners.... the old fairings from it I got later from them showed much abuse. but they were worth getting as some new pieces were in the box and it only cost $150.00 and the windshield without a scratch on it is worth that much ! likewise a new front fender well ...
....
I would say the bike is exactly like I parked it before winter and did all that stuff...Knowing the carbs were still dirty from my attempt to clean them when I first got it I sent the carbs to Gordon, he did his thing to them and sent them back after a few months sitting on the bench in their bag, I put them on... getting it to start was a bear it did not want to even pop
I finally got it to fire up and tried to adjust the fuel/air screws and then it started working half way decent.... but it would not take throttle I could get the RPM UP only by using the choke and it would rise to 3,000 RPM with no problem... but it would not take throttle.
playing with it at the edge of giving it throttle I finally got some RPM out of it
and found that the dead spot or flat spot was from idle up to 6,000 RPM and then it kicked in and ran fairly well.... obviously something is wrong and the bike is un rideable like this , so after much deliberation I decided to send the carbs back to gordon so he can have another look at them sense he offered
....
at first through this problem I was thinking it had to be a major vacuum leak
as that is exactly what it felt like .. but finally it hit me all I had to do was plug the vacuum port on the carb to isolate the carbs alone and take the smogg stuff out of the question. I did that and it still did the exact same thing ...telling me it is indeed the carbs.
....
I don't think my reasoning is flawed here, I think it's fairly straight forward
and plane, it can't be anything else at this point.
....
However....if Gordon finds nothing wrong and the carbs are in perfect working order...... that leaves me nowhere to go.... I've backed myself into a corner with no escape route ! LOL
.....
I don't know man.... it should'a worked but didn't !
....
Bob.......

[thedrewski86]

I predict we get a video from Gordon by the end of the week showing Bob's carbs running on his bike

[Bob KellyIII]

LOL Hay that works ! HAHAHAH !
Bob.....

[Triple Jim]

Sure, but just because they work on a Ducati doesn't mean...

[ducatiman]

My findings include:

an unacceptably high fuel level on the RH carb due to a sticking float valve

SOLUTION? replace BOTH float valves with new, resetting associated fuel levels
*************************************************************

slightly disolored jets likely resultant of outdoor storage

SOLUTION? ultrasonic/sodablast procedure. They look like new again. See pic for the number on the main....98. It is truly stock jetted. 38 pilots...stock.
Leading me to believe needle shimming will be required to compensate for the freer flowing exhaust currently present on the bike. THAT, in combination with the sticking float valve WAS the problem.



@bobKellyIII I'll pm u shortly. Discuss, anyone?

[Bob KellyIII]

well, Humm I didn't see black smoke out the exhaust that would point to high fuel level
but ok replace'em
...
if it has 98 jets in it now then they are too rich because the sparkplugs are almost black
can you put 95's in it ???? I wanted 100's in it but that would be much richer than it is now and I want to lean it out not make it richer i thought it must have 120's or something in it because it was so rich... but sense we know the size is 98 for the main jets I am thinking 96 or 95 would be much better and no shimming needed
.....
how did you determan the jet size that are in there ? there is no markings on them
a welders torch tip cleaner has many small sizes of wires in it and you can use it as a go-nogo gauge but you have to compair that with other known jets to get the number.
is that what you did ?....no you read it off the jet !!!! I looked on those jets there was no band and no numbers they were plane
I am sure of that.... but if that's what you say then maybe I SHOULD get glasses !!!!!! LOL....

...I noticed the dark soot looking on the jets when I first took the carbs off and sent them to you... I took the bowls off to get the jet size but there are no marks on either of them.... that dark spot is probably from back firing as it did that alot trying to get the RPM's up which it would not do .
....
I am sure I didn't bend the floats when I took the bowls off after it wouldn't run right
they haven't been adjusted by me i left them alone...
....
weird !
Bob.......

[ducatiman]

"how did you determan the jet size that are in there ? there is no markings on them"

look closely at pic #3 i posted, jet is clearly numbered

More comments tomorrow, i'm beat up, turning in now

[Bob KellyIII]

LOL ! Ok no problem Sir ! good work finding the float issue !
..... but I don't think that would have caused the flat spot
the bike was not running rich after I put the carbs back in.... hardly smoking at all in fact
but it would not take throttle....
maybe it would be best to shim the needles I don't know.... I've never done shimming
what little I have gave me flat spots ....so I quit doing that !
but the way the plugs look they definately are too rich....if I was to take a picture of them they would show black not tan....or grey so too rich in normal running.
but that could be because of the high float level too.... that would cause that !
.....
I am thinking 95 size main jets and try that and see if it runs right !
Danno what do you think ?
Jim lets hear your comments too.... I'm clueless here ! LOL
Bob........

[ducatiman]

LOOKING FORWARD:

Though giving it our best shot, be prepared to further "fine tune" your carbs, Bob as we are not likely to "nail it" immediately on the 1st try.

Black spark plugs and failure to accept throttle was, no doubt, influenced by the high fuel level due to the defective float valve. Off idle, open throttle plates and rising slides did not supply correct fuel curve. I'll contend the most affecting factor is at the beginning of needle rise .....not at the end, which is more affected by the main jet size (which still may require further tweaking).

I repeat, be prepared for further fine tuning "down the road".

For now, I'll contend adding 2 needle shims is called for at minimum. In conjunction with smaller mains? I'd strongly suggest making just 1 change at a time.

As it IS your bike, I'm open to discuss before reaching a final conclusion on which way to go...shimming or mains, pilots or some combination thereof.

I'm awaiting a jetsrus order reupping my stock of varius mains and pilots, should be here by Friday or Saturday.

In the interim, I suggest giving this thread a close read:
https://www.ninjette.org/forums/show...tting+database
concentrating on '08 and up comments (dismiss early gen and any with "pods, no airbox" )

I'll further comment your bike (with altered exhaust) was never fine tuned from PO to you as jetting is still in stock state. Time to hone in on it!

[thedrewski86]

Originally Posted by Triple Jim

Sure, but just because they work on a Ducati doesn't mean...

Now that's funny

...and wow, Gordon, good work. All I can say is that would cause me to scour ebay for a stock new-gen pipe.

[Triple Jim]

Didn't Bob say it's is a stock pipe with a slip-on muffler? (too lazy to re-read a zillion posts)

[ducatiman]

correct, TJ.
The bike should run as is even given the less restictive exhaust. I want/need to get further feedback from the owner AFA his desired jetting prior to returning the carbs after some full back and forth, even with differing opinions.

[ducatiman]

@bobKellyIII

occurs to me to ask about storage conditions of your 250 since you 1st received carbs. Outdoors or indoors? Sidestand? Leaning over fully?

[Bob KellyIII]

Gordon: the bike was stored INDOORS in the shop leaning on it's side stand
However it is not a heated shop and it got down close to zero degrees in there
I put the bike in the shop when the weather this last winter started to turn Sower, yes it did get wet a few times in the rain but almost all that time it was in the shop under cover but cold...below freezing most of the time in the 20 degree area.
Before I parked it and tore it apart to do the valves and pull the carbs to send them to you for a good cleaning the bike acted very cold blooded hard to get started most of the time it would start right up on choke but you had to keep the choke on for 5 minutes just to keep it running long enough to get warm.
once warm it would take throttle well and run very well at all RPM's
Yes this does denote that the lean spot has always been present that is why
it's so hard to warm up but once warm it was fine and took throttle without a bog... that was not the case after the cleaning it would not take throttle even after warming up.... so yes fine tuning looks like it must be done to get the bike to run perfect .
.....
.....
I think shimming the needles with 1 shim and lowering the mains to 95 is in order.... that should give me a starting point.
....
....
the bike leans fairly good on it's side stand too Gordon I had to cut it down several times to get the lean right and to stay upright in the strong winds we have.... stock lean is not enough up here in these winds it will blow over !
I'm guessing but a 35deg to 40 degree lean on the side stand ( all my bikes have that lean due to the wind! 60&70 mph winds are normal here.)
........
I do have the stock muffler but it really is a big boat anchor and I do not want to put it back on because of it's size and weight.
...
...upon doing a bunch of reading it seems shimming the needle is a very common practice on these Ninjas.... they must be very lean off idle to warrant that.... kind'a odd really !
...
...
so all the time I have had this bike it has had trouble just off idle now it's much worse.... I'ed say it's time to fix that !
after it's been running in the past for about 3 minutes if you tried to give it throttle with the choke off it would sog a bit and then take off once good and warm it would not do that.... that's not right and a symptom of the problem I have now.
....
it may very well be, that besides the float problem and too rich of jetting
that all the bike needs is fine tuning...

Bob......

[ducatiman]

can you post a pic of its sidestand lean angle?

[ducatiman]

If anyone is wondering why I'm currently focusing on the lean angle.....it could be problematic in that the RH carb innards are being exposed to
(vented) air and could actually have caused the float valve issue! Yes, possible conjecture on my part...but I'd sure like to see the actual lean angle involved. Also, could be a contributing factor to difficult starting/idling.

[Bob KellyIII]

Originally Posted by ducatiman

can you post a pic of its side-stand lean angle?

Ok sure.... this is the best shot I have of the lean angle...
that looks to be a very old picture actually.... it might be just after I got it...
let me see if I can find a more recent one.

Bob....

[Bob KellyIII]

Here is a picture of it last fall I think just before the tear down
....
Bob........

[ducatiman]

not nearly as extreme as i'd imagined, forget that issue

i'll be in contact when jets arrive BK, ok?

[Bob KellyIII]

Darn picture ! it's sideways ! there I fixed it (I think)
anyway I never let it set on it's side stand and idle I am always astride the bike and letting it idle so the bike is level when I warm it up... one of the reasons I complain about the long warm up time... it does take forever to warm up and stop sogging when you crack the throttle but it will stop....or at least it DID
.... now I am not so sure...
Yes I think 1 or 2 shims under the needles and 95 main jets Gordon....
if you think 2 shims is better than one put 2 in !!!! I think 95.9% all put in 2 shims on the forum... getting them to run correctly. I can always take a shim out, but it's real hard to add a shim later if I don't have it to do that !
.....
....if I walk away from a bike idling I turn it off... air cooled 4 stroke's get hot sitting idling and it creates a habit ! it's almost if I get off the bike i turn it off
I just don't run the bike much if I am not on it.... even adjusting the air screws
.....
I can put the rear stand under the Ninja easily enough to level it out more but I don't think the lean is that excessive....
YES in all the testing recently it was leaning on it's side stand
I didn't try straighten up the bike......I should have I guess Just didn't think about it !
....
Bob....

[Bob KellyIII]

Originally Posted by ducatiman

not nearly as extreme as i'd imagined, forget that issue

i'll be in contact when jets arrive BK, ok?

Ok sounds good.... do you think 1 or 2 shims under the needles would help?
I'ed just as well have you shim them while their there buddy !
....
let me know how much the Floats, jets and shim washers cost I will pay for them.
....

I'll be waiting to hear from you ! THANK YOU !
Bob...

[ducatiman]

As you initially overpaid me (remember?) its all on me.

Doanworryboudit (as we say in Brooklyn)

Gotta check for shim whereabouts...where the heck did I put them?

I'll be in contact by Saturday for sure.

[Bob KellyIII]

LOL OOOk ! Yes I do remember that part ! I am thinking 2 shims under the needles now the more I read the more the guys are using 2 shims so lets plan on 2 shims please..... well when the parts actually come in that is !
.... I am in no Hurry Gordon ! I am playing with the XR650L at the moment
trying to get the Samdo speedometer hooked up on it....
I have to do each wire separately so it is a slow arduous job...
but I just now finally got power to the unit and it does light up ! and it does look very cool....
it may take me weeks to get it working like it should but the end results should really be worth it... I really like LCD dashes on bikes ! the RX4 spoiled me !
....
Later my friend !
Bob.....

[Bob KellyIII]

SO YES ! 2 shims and 95 mains Gordon I just re-read where you Did sujest that !
so I am all on board with your sujestions !
.... I bet it will run like a champ now !
Might be worth it to take off the 16 T sprocket and put the smaller one back on and see if it wheelies with a blip of the throttle ! HAHAHAHA ! its a 350lb bike though I doubt that it could ! but with a crisp running engine it may well do just that !
....does your bikes do that guys ? or do you have to "clutch it up"
as low geared as the Ninja is I would think it just might wheelie with a blip of the throttle ! that would be super cool !
....
Bob......

[ducatiman]

https://faq.ninja250.org/wiki/File:Routing.gif

CA vac line routing , Bob you may want to review this

[Bob KellyIII]

thanks Gordon but that is not like mine at all.....
I dug up some old photos that I took long before I took it apart so I know I did have it hooked up right !
my bike has the 3 hoses on the side of the gas tank and a PVC valve in the works that is vacuum operated.... seems they have several versions of the CA model over the years !
....
i got the speedo to work on the XR650L a bit ago..... now for the tachometer !
.....
Bob....

[DannoXYZ]

Originally Posted by Bob KellyIII

Howdy Danno !
I agree with your statements on the shimming of the needle, I probably didn't make myself clear on that.... but like you say it is exactly like putting in a bigger mainjet because you are actually pulling up the needle out of the main jet when you do the shimming...(in effect anyway, the needle sticks into the emulsifer tube not the jet itself but it is close !)
....

Take look at this photo. Main jet is at opposite end of emulsion tube and needle doesn't affect its metering as much as needle-jet/collar at other end. The gap between needle and needle-jet changes dramatically with height of needle from slide's closed position to fully open.



Shimming needle only affects mid-range because tip of needle doesn't change at all (see pics below). Most change in needle's diameter is in mid-range. Once you get to 10k+, needle-diameter remains constant-diameter. So even if it lifts up out of needle-jet more, it doesn't change fuel-metering because gap remains constant. This matches with engine's loss of VE in higher-RPMs and loss of torque (max-power is around 10K). So changing needle-position with shims won't affect high-end fueling at all.

However, changing main-jet will affect mixtures across board from mid-range onwards. Which is not what we want to do when adjusting only mid-range-fueling since top-end is already too rich anyway. No need to add even more petrol to already super-rich high-end.

Notice differences in factory new-gen needle vs. DynoJet's stg-II needle:


Mid-range on DynoJet needle is thinner than factory for extra fuel in mid-range. While tip is much, much fatter to remove LOTS of high-end fuel.

[DannoXYZ]

Bob, I recommend you run carbs in as-delivered configuration without changing anything. Muffler-only upgrade does NOT require any jetting changes. It's full-exhaust that changes flow significantly enough to require it.

As with everything else, make small incremental changes so that you'll know what change caused what effect.

Since you have new-gen, hoses and emissions connections are slightly different. However, do post photos of your original vacuum connections; they may actually be incorrect. Never, ever trust what PO tells you or have done on bike! Verify everything!!!.

On new-gens, emissions is simpler, so you don't have to do much:

1. leave ALL connections to tank alone. EVAP canister is standalone system and doesn't have anything to do with carbs.

2. disconnect ONLY small vacuum-line from "CA emissions-fitting" going up to PAIR valve on top of head, under tank. Cap off vacuum-ports on both ends.

3. run vacuum-lines according to this diagram, it's better than new-gen's factory configuration. It gives petcock its own dedicated vacuum-line to ensure maximum-vacuum for reliable operations. Then 2nd vacuum line goes to decel-valve. A vacuum-leak here due to cracked lines or insufficient sealing at ends won't affect bike's operation much (compared to having it on other vacuum-port). So basically just swap vacuum-hoses coming off vacuum-ports on carbs.

Note vacuum-T that you've capped off that used to go up towards PAIR valve.

[Bob KellyIII]

OK you wanted to see the pics of the hoses.... so here they are....
....
Bob....

[Bob KellyIII]

and I do like that vacuum hose arrangement better in your picture because the stock way gives very little vacuum to the petcock I noticed that when I put the in line filter on
it would only flow gas too the filter when at max vacuum ! like revving it up and then closing the throttle THEN gas would flow.... not perfect by any means. but it did work.
.... the pictures are hard to see
but that is what I have to work with.... not much help actually ! HA !
I did finally have to resort to diagrams on the manual appendix to get it right.
.....
Ok Gordon I will take them out of their box and put them in without touching anything!
I promise ! the only thing I will touch is the air screws to get the idle right.
(this last time they didn't really want to work very good anyway) (rt one didn't change a thing) probably because of the float height.
.....
later !
Bob.......

[ducatiman]

Originally Posted by Bob KellyIII

Ok Gordon I will take them out of their box and put them in without touching anything!
I promise ! the only thing I will touch is the air screws to get the idle right.

later !
Bob.......

Ok, revue to be clear....stock setup? or shimmed, down-jetted as prior requested?

[Bob KellyIII]

not stock this time.... 95 main jets and 2 shims under each needle and we'll try that.
.....
I honestly think that will fix the problem....
Bob....

[Triple Jim]

That photo reminds me of our '57 Citroën DS we had when I was a kid. Its hydraulic suspension would leak down overnight, so when you'd look at it in the morning it was pretty close to the driveway. The difference is that when you started it, it would quickly pump up to normal ride height.

[ducatiman]

Originally Posted by Bob KellyIII

not stock this time.... 95 main jets and 2 shims under each needle and we'll try that.
.....
I honestly think that will fix the problem....
Bob....

I'll return your stock 98 mains as well, just in case.

I'll get to post Monday am.

[Bob KellyIII]

Yes Triple Jim the bike is alot lower than stock.... I have a lowering kit on it and have raised the forks almost 2" on the front to match the rear so it's short and squat !
I can walk up and swing a leg over the seat without having to step on the foot peg on that bike ! ... it just looks smaller than normal now ! kind'a neat actually !
.....
Gordon: 95 mains and 2 shims ! just for re-affirming.....
and I'll tweak it from there as it may well need fine tuning.
....
Danno the close up's on the jet needles really do show quite a difference there...
and like you say the area where Mid range RPM is at is fairly flat and you can easily see
why the ninja's are fat at WOT .... interesting ! it may well be worth buying new needles in the future !
I think the snorkel is still on my Ninja.... I haven't taken it off but the previous owner may have.... if that really improves air flow it is probably worth doing but ONLY later after I get it going again and it takes throttle..... you know, one thing at a time !
I have a tendency to make several changes at once and it usually gets me into trouble !
....
I got the Samdo speedo and tach working and am moving on to turn signal and neutral lights on Big Red ! then I'll button it up and go for a ride !
.....
Bob.......

[DannoXYZ]

Originally Posted by Bob KellyIII

and I do like that vacuum hose arrangement better in your picture because the stock way gives very little vacuum to the petcock I noticed that when I put the in line filter on
it would only flow gas too the filter when at max vacuum ! like revving it up and then closing the throttle THEN gas would flow.... not perfect by any means. but it did work.

That's not working properly and is reason you don't have any petrol in your carb bowls. Verify if petcock still operates this way when you get carbs re-installed. If it does, problem is with petcock not flowing properly. It should flow abundantly at idle, no revving/closing throttle needed to make it flow. May need to measure actual vacuum levels in those hoses.

[Bob KellyIII]

Yah I agree ! that is definitely not right but up to that point I hadn't experienced any "Running out'a gas" symptoms....LOL.
I think hooking the vacuum lines up slightly differently will cure that problem though.
.....
Typical spring day here RAIN ! cloudy over cast and cold.... not something I want to be outside in so I'm staying inside by the fire !
....
Mine is hooked up slightly different than the pic you showed Danno (thanks for the easy to see pic !) so it's fairly easy to put the "T" in the straight hose to the decell valve on the carb.... I think that will work alot better !
.... I'll get around to that fairly soon.
I think I will wait till after I try out the carbs on it first though.... I don't want to change anything right now ! even as mundane as that is ! LOL

Bob......

[Bob KellyIII]

Well, My carbs should be back here tomorrow... so that's cool....
....
I tried out my new $200.00 welder on welding up the hand guard that i broke on the Kids TT250 the other day... and it did a good job...can't complain at all !
...this welder is supposed to be a 200amp Tig and stick welder but it came without a flow regulator or bottle of argon.... those I will have to get later....
but as far as welding DC stick aluminum rod (nasty stuff on it's good day!) it actually worked better than I remember it working on my Old DC welder ! ...
I built up the airea around where the thing broke so it should be stronger now...
$29.00 for 1/4lb of that aluminum welding rod now....OUCH ! and I used 2 rods already
that stuff is really hard to work with...it covers everything with it's flux a sodium based flux that runs everywhere ! so you gott'a chip it off and off the tip of the rod before you can strike an arc... it took me about an hour to weld it.... I tried something new this time.... I pre heated the part with a propane torch and I do think that helped quite a bit
it was a small weld job but I had the welder set at 100 amps because I know these cheap welders are very generous on their read outs...
it was a battle using that SALT ROD as some call it... but it did coat the part good and it LOOKS alot sturdier than it was.... we'll see I guess.
I mainly got that welder because it was a cheap TIG I need that to silicone bronze braze the gear teeth in the Logan 922 lathe I have.... it's got some tore up gears in it and one of the previous owners used the screw method of replacing missing teeth in the bull gear.... it works but it makes a tic,tic,tic. sound when running it in back gears.
and I have one other gear I need to fix too ...it looks like a bolt fell into that one while it was running.... it's tore up pirty bad, so I made another gear out of aluminum to replace it with.... but I can fix that gear now that I can braze with the silicone bronze
.... I don't know if I need argon for just brazing or not... all the video's show the guys using it, but is it NECESSARY or not is my question.... i don't think so because your just using the torch to Heat.... not to melt the metal your bonding the bronze to
.... so I might try it without the argon ! LOL... what have I got to loose but a $5.00 stick of silicone bronze ? yah that stuff is outrageous in price !!!!
....
I really need to get the Ninja out of the shop !!! I need the room !
it's the size of a single car garage and with a bench along one wall and the lathe along the other there is about 6' between them...and the Ninja in in the Middle of that ! LOL
.... needless to say I have to be real careful on how I walk around in there at the moment.
....
I'll let ya know if the carbs come tomorrow !
...
Bob......