ok...so last weekend kkim shimmed my carb mixture needles on my '03 250. sorry, didn't plan to post a d.i.y. because...well, i didn't do it myself!

what a difference it's made! the bike starts much more readily, i dont have to tinker with the idle speed, AND the bottom end of the bike has come to life! if you've considered shimming your mixture needles i'd recommend you go for it!

ahh..get someone who knows what they're doing iffn ya aint doin it yerself! you'll be pleased with the difference!

aloha

Steve,

Glad the shimming worked out for ya and you like the bottom end your bike has found.

Like I said, find out about what it takes to pull the snorkel and we can set up your bike to pull even harder on the top end as well. :D

Steve,

Glad the shimming worked out for ya and you like the bottom end your bike has found.

Like I said, find out about what it takes to pull the snorkel and we can set up your bike to pull even harder on the top end as well. :D

:decision: ummm...ok! sounds good! :dance:

KIM! Get yeeself on a big silver tube and jet over to Twoson. I keep getting slapped with all these grand posts about this washer thaingy. If I hear just 1 more good thing about it I might blow up or something.....but I just can't bring meeself to rip into 2 perfectly good running carbs....because I just KNOW that they won't be 2 good running carbs after I put them back together. :mad:
:yell: Happens all the time with my mods!

First post on this forum. I've got Two Brothers on my 07 and I get the hesitation on the bottom end from time to time but never any starting issues. I'd like to do the shim mod but the last time I took apart a carb was on a 60's snapper lawn mower. Any suggestions? Any links to a good DIY? Thanks!
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KIM! Get yeeself on a big silver tube and jet over to Twoson. I keep getting slapped with all these grand posts about this washer thaingy. If I hear just 1 more good thing about it I might blow up or something.....but I just can't bring meeself to rip into 2 perfectly good running carbs....because I just KNOW that they won't be 2 good running carbs after I put them back together. :mad:
:yell: Happens all the time with my mods!

Yep, shimming those needles really boosted the smile factor while riding by ninja, it really made it ALOT more FUN. It is really A GREAT RIDE now that I have shimmed my needles.

PLEASE take a video of when you :boom:

yeah I know, I'm a smart a**.

Check the DYI that kkim has posted on here, Sound_wave and I did mine and it took about an hour or so, from the time we started taking off the fairings to washing our paws. Really easy, if you have tinkered with mechanical things in the past, you can do this. And if you have any problems, post it on here and you will get answers almost around the clock.

nb

hey jon welcome to the forum :yo:

i have the stock exhaust on my '03 and the shims suited my machine well. with an aftermarket exhaust installed, although i'm sure shims would enhance your performance, i'd look into possibly rejetting to get the performance desired w/ your pipe.

i'm not sure if there are any D.I. Y. threads for shim installation on the '07 in particular, but here's a thread that details whats involved.

http://www.ninjette.org/forums/showthread.php?t=11963

Yep, shimming those needles really boosted the smile factor while riding by ninja, it really made it ALOT more FUN. It is really A GREAT RIDE now that I have shimmed my needles.

PLEASE take a video of when you :boom:

yeah I know, I'm a smart a**.

Check the DYI that kkim has posted on here, Sound_wave and I did mine and it took about an hour or so, from the time we started taking off the fairings to washing our paws. Really easy, if you have tinkered with mechanical things in the past, you can do this. And if you have any problems, post it on here and you will get answers almost around the clock.

nb

Yep, shimming those needles really boosted the smile factor while riding by ninja, it really made it ALOT more FUN. It is really A GREAT RIDE now that I have shimmed my needles.

PLEASE take a video of when you :boom:

yeah I know, I'm a smart a**.

Check the DYI that kkim has posted on here, Sound_wave and I did mine and it took about an hour or so, from the time we started taking off the fairings to washing our paws. Really easy, if you have tinkered with mechanical things in the past, you can do this. And if you have any problems, post it on here and you will get answers almost around the clock.

nb

:bash::confused10: U B a funny man alright! However, you did it to your toy, so I raccoon I can do's it to mine. The real thing is, I can't visualize how to attach these extra washers onto the needle. How do these Radio Shack 4MM washers attach??

Imagine a common nail, which is shaped like a "T". All you're doing is turning the nail upside down and putting 2 washers on it, along with a little bit of grease or vaseline. When you turn the nail rideside up, in order to reinsert it into the carb, the grease keeps the washers from falling off. :thumbup:

yep... one needle shown w/ shims and one without...

http://lh4.ggpht.com/_geC920GCq38/SLkSz8IDsVI/AAAAAAAAA0E/b4DqoHye5fg/s640/DSC04542-1.JPG

feel free to browse through this album to see jetting and airbox removal pictures.
http://picasaweb.google.com/kkim993/AirboxAndRejet#

Thanks everyone. I appreciate the feedback! I believe I'm going to have to take the carbs completely off for this job. Here's why: I got the bike last year from the dealer, brand new, with the Two Brothers slip-ons. I don't know if they have already shimmed the needles at the dealer when they put on the slips. I figured taking the carbs off and taking the needles out with the carbs on the side will make sure that if there are washers in there, they don't get lost. I don't think it would be that easy to tell with the carbs in the bike. Or I could be wrong?

Either way. This weekend's plan is to first shim the needles and clear the idle mixture plugs. See how she rides and make sure everything is good after about 50 miles of riding.

Then, I will adjust the idle mixture using the Wiki method. Ride it around and see make sure everything is good. Then, I'll sync the carbs.

Now I just need some nice weather for Sat/Sun.

Jon,

no need to remove the carbs to shim the needles... that's what makes it such a great mod... plus it's cheap. :D

you only need to access the top of the carbs by pulling the fairing out a bit so you can remove the gas tank to get to the carb tops.

this is for a 08/09 bike, but it's basically the same once you get the tank off.

http://www.ninjette.org/forums/showthread.php?t=11963

yep... one needle shown w/ shims and one without...

http://lh4.ggpht.com/_geC920GCq38/SLkSz8IDsVI/AAAAAAAAA0E/b4DqoHye5fg/s640/DSC04542-1.JPG

feel free to browse through this album to see jetting and airbox removal pictures.
http://picasaweb.google.com/kkim993/AirboxAndRejet#

so...the washers just stay on the needle when it is turned over to reinsert into the carb top? I assume that the needle never rises so high after reinstallation that the washers move off where they are supposed to be inside the carb body?

nope. there's a long spring inside the carb top that pushes down to keep everything seated.

http://www.multisurfacemotorcycling.com/klrpage/carb/carb06.htm

nope. there's a long spring inside the carb top that pushes down to keep everything seated.

http://www.multisurfacemotorcycling.com/klrpage/carb/carb06.htm

OK then, Cheers! :martini-drinking:

Jon,

no need to remove the carbs to shim the needles... that's what makes it such a great mod... plus it's cheap. :D

you only need to access the top of the carbs by pulling the fairing out a bit so you can remove the gas tank to get to the carb tops.

this is for a 08/09 bike, but it's basically the same once you get the tank off.

http://www.ninjette.org/forums/showthread.php?t=11963

Ok cool. The bike was bought new w/ the slip-ons already on the bike. The only reason why i was considering was b/c if they already shimmed it at the dealer, i didn't want to pull the needle and have the washers still in there and mess something up. I'm guessing there is a needle retainer like how they show in the KLR650 link right? I guess I'll find out soon (like this weekend)!! :thumbup:

jon, there is a needle retainer, but it sits on top of the needle head. i would imagine that if it is already shimmed and you pulled out the needle, the washers may fall off.

i believe you would be able to tell by just looking down into the hole if there are washers on the needle. if they did, maybe you could add another shim. if they didn't then you could do the mod.

if the washers do fall off when you are trying to remove the needle, you could try tweezers. or a magnetic pick-up wand (still dying to use mine for something). you could actually remove that whole diaphragm part, but it seems really fragile and i would be afraid to tear it.

anyways, good luck.

Thanks for the advice everyone. I did the mod the other night and so far so good. I did decide to take the carbs out entirely because there was no way I'd be able to get the plugs off the idle mixture screws.
http://faq.ninja250.org/wiki/How_do_I_remove_the_carbs_to_work_on_them%3F
It would have also been a real tight fit to get the needles out of there as well, but it is possible to get the needles out without removing the carbs. You just need a good set of mini needle nose pliers that are a tad longer than usual.

The most difficult part of this task (if your taking the carbs out), is getting the boots boots off the engine and the boots off the intake to allow you to remove the carbs. The boots are what holds the carbs on the bike (minus the throttle and choke cable). My suggestion on this is to remove the metal bands that are on the engine intake boots so that the boots are as flexible as possible. Make sure you have a perfect fitting phillips screw driver. The screws on the carbs covers are rather soft. If your unplugging the idle mixture screws, just realize that the plugs are only about an 1/8 to 1/4 inch deep so you don't have to go crazy drilling. Also, the wiki doesn't mention this, but you should remove the bracket that the airbox fits into by the carbs. It allows you to move it around more which is important for getting the airbox boots off.

I found that the needles were not already shimmed. I used three #4 washers that I was able to get from Radio Shack. They come in an assorted 100 pack that costs $1.99 which is essentially the entire cost of this mod plus the time it takes to do it. I found that the bike pulls harder and smoother in general. Low end stumble has been eliminated. However, I do have a slight mid range stumble that was probably there before but I never noticed because the bike was never this smooth before. IMO, it'll never be perfect even if it was re-jetted and this is as good as it is going to get.

Next project will be to make sure the carbs are in sync and readjust the idle mixture screws once the weather gets a bit warmer.

Thanks again for all the advise!!!

Jon,

Good job. Is the midrange stumble when you are cruising on the highway under light throttle openings or during hard acceleration? What rpm does it stumble at?

Jon,

Good job. Is the midrange stumble when you are cruising on the highway under light throttle openings or during hard acceleration? What rpm does it stumble at?

The stumble occurs approximately at about 5-6k RPM at speeds of about 40 MPH. So I'm just basically cruising for MPG, stuck with some cars and I'll lightly open the throttle and get a stumble for a half second to a second. It's definitely a stumble because you get that kind of neutral feeling for that quick second.

sounds like the mixture screws might need to be richened up a bit. How did you determine where to set them and what are the set to now?

3 washers are plenty, though, so it may be that you are a tad rich off the bottom, so again, playing with the mixture screws might lessen the stumble by leaning it a bit.

without actually being there, it's hard to tell which it is.

Excellent point as usual. I reset my mixture screws to default which is 2.5 turns out from all the way in. When I warmed up the bike, it idled correctly at first and then after some riding i got floating rpms at around 2k. I was able to correct this by just actually lowering the idle speed with the speed adjustment knob and the issue went away. I can blip the throttle after being fully warmed and there is no floating.

Maybe I should turn the idle speed knob back to where it was (there is some play where turning a half turn or so will not affect idle), take it for a spin, then the rpms should hang again. At this point I can lean it out with the mixture screws until hanging stops... What do you think? I've got time to do this tomorrow.

hey jon
glad to read you've done the mod and things are going ok tweaking aside.

good on ya! :thumbup:

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

I used the alternate method.

If yours is hanging, it sounds like it's set a bit lean, which would coincide with the stuttering you're getting on light throttle settings when cruising. I really think richening your idle mixture (ccw) by a 1/4 turn or so will solve your problem.

I used the alternate method as well and it is currently fine at idle. I'm definitely going to play around with the mixture screws anyway and see what happens. First thing I really need is a nice screwdriver. Instead of ordering "SuperStubby (http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=35438)". Does anyone know where I can get something similar local? I checked Home Depot without any luck.

I ordered and use the super stubby. Vex uses the Milwaukee offset screwdriver. I have one of them too, but I'm too clumsy to use it and like the little screwdrivers better for tuning the mixture screws. If your hands are small enough, you can get in there with a screwdriver bit and turn them, I think.

wear gloves... it gets hot in there if you use the stubbies.

:D