DIY Shimming the carb needles.

[newrider74]

okay i tried to do this mod tonight and didn't take out the carb. well, being a dumba$$ i managed to strip one of the screws on the carb. had to put everything back and give up on this mod as i can't get the screw out.

does anyone live near the torrance, california area that has a dremmel or a way to remove the stripped screw and do this mod for me? i am willing to pay $50 or so. please send me a pm if you're interested. thanks.

[headshrink]

$50 should get you a dremmel

[newrider74]

Originally Posted by headshrink

$50 should get you a dremmel

true.. but i don't want a dremmel.. i just want my needles shimmed lol.. i guess i'll have to get a dremmel and do it myself if no one is interested. this is going to suck since i'll have to fully take out the carb.

+1 on "i threaded my screws trying to do this mod" lol

[Momaru]

I managed to strip a screw doing this too, but with a little time and a pair of needle-nose vice-grips managed to get it loose. Happen to have a pair and/or a pair of needle-nose pliers with some good teeth?

[newrider74]

Originally Posted by Momaru

I managed to strip a screw doing this too, but with a little time and a pair of needle-nose vice-grips managed to get it loose. Happen to have a pair and/or a pair of needle-nose pliers with some good teeth?

yes i do. how hard is it to take out the whole carb for this mod? there's no way i can remove the screws now with the carb on the bike. also, where would i get replacement screws? anyone know the size?

[headshrink]

You don't need to take out the whole carb.... just remove the tank, and any hose that is in the way (take pictures of how they are routed/connected first). It would be a good idea to have a 90 degree driver like the one mentioned earlier in this thread.... even if you don't have one, this is the time to get one - you WILL use it again.

[Momaru]

Originally Posted by newrider74

where would i get replacement screws? anyone know the size?

I mangaged to find some at my local hardware store, under 'metric pan head screws.' You could order some online (below) but you'd be overpaying a bunch + waiting on them to arrive.

Size (obviously) depends on which screw it is you mangled. I'll assume it's on the top of the carbs holding the black cap that covers the needle/diaphragm since you're working on the needles, so those are 4mm x 18mm screw. I recommend getting a few of that size as well as a few 4x14 screws, which fit the float bowls for changing main jets if/when you plan to. Pretty sure we use a 0.7 thread pitch on both kinds of screws; the 0.7's I got fit just fine, but I've got an '08

If this isn't it, check the spec sheets @ http://www.kawasakipartsnation.com, Ronayers or the Kawasaki home site, 'under carburetor' or 'carburetor parts'

As far as removing the carb from the bike, I don't know. Managed to get my mangled screws free w/o pulling the carb, but I'd be surprised if there isn't a DIY around here somewhere for that. I do know it's quite a few hoses to disconnect, so make sure you remember/label where each goes.

[kkim]

Originally Posted by Momaru

As far as removing the carb from the bike, I don't know. Managed to get my mangled screws free w/o pulling the carb, but I'd be surprised if there isn't a DIY around here somewhere for that. I do know it's quite a few hoses to disconnect, so make sure you remember/label where each goes.

http://www.kawiforums.com/ninja-250r...ll-re-jet.html

[ninja250]

Just shimmed my needles.
Already had the snorkel out.

This should hold me over till I get the jet kit and K&N bi-pod.
Will report how it feels later. Thanks for the tutorial.

Used a $16 Husky brand ratcheting 1/4" driver from home depot for the screws. Comes with perfect #2 bit. Not an inkling of stripping the screws out with this. You are able to apply plenty of force on the screw.

Shimming needles = 2/10 difficulty. Only cause you have to remove the plastics and tank.

[HKr1]

Originally Posted by ninja250

Shimming needles = 2/10 difficulty. Only cause you have to remove the plastics and tank.

I just slide the tank out from between them plastics(shop rag on each side). Iam pretty dam lazy at times

[ninja250]

oooooh yeah. You got me.

Now to remove all this California air regurgitation system.

[ninja250]

Whaaaaat! Holy Powerband Batman! Shimming my needles must have been the best choice I could have made for this bike without spending any money!

Sheesh my bike was boggin' bad off the line before with just the snorkel removed and now when you smack it open from stop or a rolling start she jumps up and goes! No laggin' before making the power. Definitely feels like a fatter powerband.

Bike did warm up faster. Also only warmed up to 3k instead of the normal 3.5kish
I suppose that's good enough, I can leave it there without having to work the choke lever much.

My idle RPM after warm did not change from doing this mod at all.

Much easier to operate the bike like this when it is cold since it goes off the line no hesitation. Indeed makes the bike more beginner friendly even though that wasn't why I did it.

I would highly recommend this to anyone who hasn't done it! Major improvement, totally made it a new bike to ride! Much more enjoyable! Also did the kleen air removal and capping. Need to do exhaust, jetting and intake filter now! Woot!

[headshrink]

Originally Posted by ninja250

Just shimmed my needles.
Already had the snorkel out.

This should hold me over till I get the jet kit and K&N bi-pod.
Will report how it feels later. Thanks for the tutorial.

Used a $16 Husky brand ratcheting 1/4" driver from home depot for the screws. Comes with perfect #2 bit. Not an inkling of stripping the screws out with this. You are able to apply plenty of force on the screw.

Shimming needles = 2/10 difficulty. Only cause you have to remove the plastics and tank.

Good idea.... I have a tool like that, but didn't even think to use it. I also like how you labeled the hoses.

[ninja250]

Was gonna post more pics here but guess I'll just start my own little mod thread so I don't trample all over everyone's DIY work.

[newrider74]

Originally Posted by ninja250

Was gonna post more pics here but guess I'll just start my own little mod thread so I don't trample all over everyone's DIY work.

thanks for the tool tip.. i went out and bought one and got the job done. took the bike for a ride and it seems smoother... no more stalling at the light due to engine not warm enough... this will give me more confident in my riding for sure.

[g21-30]

Originally Posted by ninja250

Was gonna post more pics here but guess I'll just start my own little mod thread so I don't trample all over everyone's DIY work.

Don't think kkim will mind. Post away in this thread, as long as it's related to "Shimming the carb needles". After all, that's the purpose of the DIYs, i.e. show how to do it and then see the results of others using the DIY to do it yourself!!

[kiwi 250r]

A lot of people describe the performance of the stock 250r in the low gears/RPMs as "boggy". But can someone describe what it actually feels like?

I am new to the 250r (and bikes in general so learning curve is high at the moment so please bear with me ). My 250r is completly stock and I have no problems taking off, it doesn't splutter or feel like it's going to stall when cold like some others have described. I don't need to use the choke at all from cold and idles perfect when warm. But....

what I have found is a real lack of power from stop until 3rd gear. In 1st it feels like the bike is really screaming at mid-range RPMs and lacks pull. It feels like it's geared to high/tall.

2nd isn't as bad as 1st but still not good....it's not until 3rd where I can feel some good pull and balance. 1st is also very jerky and sometimes I stuggle to keep a constant feel when moving very slowly (say in a car park).

Maybe I'm just not giving it enough throttle but I sort of feel I shouldnt have to rev the cr@p out of it to get a smooth performance.

Am I describing what others have also felt when riding the stock 250r?

[g21-30]

Originally Posted by kiwi 250r

A lot of people describe the performance of the stock 250r in the low gears/RPMs as "boggy". But can someone describe what it actually feels like?

1st is also very jerky and sometimes I stuggle to keep a constant feel when moving very slowly (say in a car park).

Maybe I'm just not giving it enough throttle but I sort of feel I shouldnt have to rev the cr@p out of it to get a smooth performance.

Am I describing what others have also felt when riding the stock 250r?

I cut your quote down. First "boggy" usually means when you give a vehicle (car/bike) more gas, it initially kind of falls on it's face. It wants to go, but it hesitates and then takes off. It's that lag that is called a "bog!" Many times it is from more air than gas coming thru the intake, which of course, is a lean condition.

1st being jerky can be fixed by shimming your needles, but this is assuming that you're not having clutch issues (not mechanical) meaning you're the one causing the problem. By you having to rev it definitely means the engine is running too lean in first gear. Another reason to shim the needles.

[kiwi 250r]

From your description of boggy I don't have that problem as the response is good. The response I get is just weak and lacks ooommph until 3rd.

Shimming the needles will be my next project....when scooters can kinda keep up until 3rd gear there's got to be a solution.

[ninja250]

kiwi,
It does sound like you can benefit from this mod. That weak response will improve.

Mine wasn't exactly bogging that I noticed (much) but being a gearhead I could feel the lag when I opened the juice a bit. Power band is something I will note changes in. When you perform this mod you will realize where it was bogging previously. She will feel like a new bike in the lower gears and smoothen out quite a bit.

I need to fix my weak top end now with a jet kit. Power falls off or levels out after 10k.

[killerkay3]

just to clarify....when you buy a jetkit they give different needles and washers to replace the stock? is that all re-jetting is?

[ninja250]

That's half of it. Then you have to pick the right jet and needle settings to tune them to the rest of your bike.
I believe some of the jet kits come with several different sized jets, some carb screws, springs, a drill bit and adjustable needles.

Usually if you say you jetted your bike, you installed a jet kit and then tested it in some way to be sure it was the right jet and is tuned right.

[ASecretNinja]

Hi guys, sorry I am at work and don't have time to wade through all 13 pages of this thread, but is the procedure for this similar on the pregens?

[Snake]

Yes the procedure is the same. This thread has some setting that others have tried. http://www.ninjette.org/forums/showt...tting+database

[Tripyn]

Well, after reading the majority of this thread I am going to try this on Monday. The local nut and bolt shop should have the allen head screws/washers in stainless (been down that road before) and sears should have that ratching wrench. With our lil NInja it seems to stumble in the mid range so I am hoping this will help. We are right at sea level so I plan to try one washer, test it, then removel snorkel add a washer and see what I get. I have learned that jetting is a fine art and requires A LOT of patience, I learned this from my 450r race quad and it does pay off in the end.

Thanks for all the info folks.....I will post my results next week.

[ninja250]

Originally Posted by Tripyn

Well, after reading the majority of this thread I am going to try this on Monday. The local nut and bolt shop should have the allen head screws/washers in stainless (been down that road before) and sears should have that ratching wrench. With our lil NInja it seems to stumble in the mid range so I am hoping this will help. We are right at sea level so I plan to try one washer, test it, then removel snorkel add a washer and see what I get. I have learned that jetting is a fine art and requires A LOT of patience, I learned this from my 450r race quad and it does pay off in the end.

Thanks for all the info folks.....I will post my results next week.

Sounds like you know what needs to be done.
Have fun My bike improved 10 fold when I shimmed the needles to two shims after pulling the snorkel. Your mid range should perk right up. Night and day difference. It's almost unbelievable what $1.00 in washers will do for this thing. lol

[kkim]

http://www.ninjette.org/forums/showthread.php?t=9465

[DarkNinja52]

Im considering doing this while I have the plastics off my bike, from what I've read it seems worth it. I understand what it does in an overall sense, but could anyone describe what is actually happening in the carbs before and after the needles are introduced?

Keep in mind I've never worked on a car/bike nor do I even really know what a carburetor is or does. If the answers I'm looking for are somewhere in these 13 pages, then I apologize, I got distracted a few times while trying to read all of them.

[ninja250]

I'm not positive.. but I'll take a swing at answering that question.
I think the shims are pulling the needle out of the jet tube more, (raising the needle) letting more gas into the mixture and richening the bike up.

Stock, it runs lean. AKA, it's thirsty and doesn't get enough gas so it likes to bog in some areas. Adjusting the needles takes care of mid range gas. When you do this mod, you will notice your mid range acceleration and power increase about twice what they were. Also, the bike will be much more forgiving at lower speeds and less boggy off the line. It will feel like you have throttle to spare now where you had to wait for hesitation for the throttle to kick in before. Throttle hesitation is not safe at low speeds.

I don't care if everyone thinks they don't need to mod their bike, it still needs to be shimmed to ride much smoother from the factory settings. The only reason someone shouldn't try it is if they don't have the proper skills to add the shims. (this means taking important pieces apart that effect how the bike runs if you mess them up!)

When I see people who refuse to mod their bike.. I feel bad knowing how much better it could run. If their only concern is gas mileage then I guess they can forget about this mod and run their bike lean and boggy forever. Otherwise, no reason not to add shims.

[adouglas]

If you've never worked on a vehicle and don't even know what a carb is then I humbly suggest that taking this project on as the very first thing you do is not a particularly good idea.

As in, WHAT ARE YOU, NUTS OR SOMETHING? <insert virtual dope slap here>

If you mess it up, you're screwed and you won't even be able to ride the bike to the dealer to fix what you did wrong.

EVERYBODY messes things up when they're learning. That's what learning is all about.

Look, the carb is in a very real sense the heart of your bike. It is also one of the most complex mechanical devices you're ever going to encounter, with many interrelated parts. Carbs can be cantankerous, finicky, sensitive and not tolerant of ignorance.

Would you want your heart surgeon to have his very first real live operation be a transplant, having never really learned how the heart works beforehand... or even knowing basic anatomy?

Start small. Change the oil. Change filters. Change plugs. Take non-critical stuff apart and put it back together again. Learn what using wrenches and removing/reinstalling (and torquing) fasteners really feels like. Experience the inevitable stripped screw/bolt.

Get the factory maintenance manual and study it.

Get a book about automotive mechanics and study it.

Educate yourself. Prepare yourself.

THEN rip your carbs apart.

[DarkNinja52]

Good talk KC. Thanks. I get the feeling that if i can get the plastics off, I think I can handle shimming the needles.

[ninja250]

Pretty much..
The toughest part about it is making sure the spring and slide boot sit properly when you put it all back together.
Also, you gotta double check the choke is working right when you're done.

I got a lot of carb tuning to do at the moment. All the scary stuff like floats and mixture screws
Be spending all day tomorrow trying to make her purr like a kitten.
(or break something trying)

[Robbo81]

Well I finally had a look at doing this same mod to a 07 zzr250 and every thing seemed to be very similar to our 250r's but this bike seems to start first go every time without the use of choke so i didn't bother. BUT. instead of having a snorkal they have a kind of hat that sits on top of the air box with 2 inlet holes on it. So i thought, hey, easy, just remove the hat in comparison to our snorkal. But you can't just remove this piece because as it slides on top of the air box it has 2 trumpets and a funny strip on it that holds the filter into place inside the airbox so no go. But maybe I could just get out a hole saw and make the trumpet holes bigger for better induction. But as for carb shimming, These bikes don't seem to run as lean as ours.

[Momaru]

Sounds like a PitA compared to just yanking the snorkel. Any chance we could see some pics?

[Robbo81]

I'll talk to my mate about carrying out this mod and if he agree's to it I'll get some pics. Its actually not as hard as it sounds. Would most likely take less time then our bikes, and alot easier to access those stupid JIS screws too.

[Robbo81]

This is the part of the air box I think you would have to modify. See the little snorkal things. pretty sure I could just chop these things off to get a better amount of air into the carbs (plus deep induction sound ) and still be able to use the lid to hold the filter into place.

Did a bit more reading and i've heard zzr's run pretty lean to so I guess you would need to shim the needles also

[dulplay]

Thank you for this thread!!! I just finished the mod about an hour ago, and I love it already! Just the fact that I was able to pull it off without catastrophe, has me smiling... Thanks to KKim and everyone else that has posted on this subject. Reading your posts gave me the courage to finally just do the damn thing! Now for that snorkel...

[kevlarorc]

ok so today I made a second attempt at this DIY as my first one failed.
After 7 hours of bike stripping, screw stripping, runs to the hardware store for new screws, runs to a different hardware store because none of my hex keys fit the new screws, vice gripping to get stripped screws out, and more torture; I got the bike back together.
It was all totally worth it. A learning experience (make sure your dremel disc is thin enough for it to actually cut a slot in a screw head) and it runs great now. I only took it around the block and down the feeder but it did 30mph - 70 mph in like 2 seconds. It also feels so much better pulling away from a stop. Freakin awesome. So glad I did this and thanks for all the help from this awesome thread.

[g21-30]

For those of you having problems finding Needle Shims, here is a source for "OFFICIAL KEIHIN FACTORY" shims:

http://www.motorcyclecarbs.com/Jet_N..._P10478C69.cfm

[kkim]

Originally Posted by g21-30

For those of you having problems finding Needle Shims, here is a source for "OFFICIAL KEIHIN FACTORY" shims:

http://www.motorcyclecarbs.com/Jet_N..._P10478C69.cfm

thanks for the link to that site!