DIY Shimming the carb needles.

[europachris]

Originally Posted by kkim

thanks for the link to that site!

I found some PERFECT shims in my old OLD stash of R/C car hardware. 3mm washers about .020" thick and the OD of the washers matched perfectly to the top of the needle.

So, if anyone has a hobby shop nearby that carries Tamiya R/C cars, you should be able to score some washers there, although my washers are "vintage", circa 1987.

[kkim]

Chris,

It was the other Keihin parts on that site that had me drooling.

[peter330]

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

Are these the right size. Want to be sure before I order them.

[tabogon]

When you say 3mm washers, do you mean in total diameter or the inner opening?

[europachris]

Originally Posted by tabogon

When you say 3mm washers, do you mean in total diameter or the inner opening?

3mm I.D. (inside)

[tabogon]

Thanks euro, I picked up a few earlier, and didn't even think to ask. haha

[kkim]

Originally Posted by europachris

3mm I.D. (inside)

actually, the 3mm should be the OD.

[tabogon]

3mm OD is a very small washer, I guess I will have to pull the needle and take one down to the store with me. Might have to dig around for my old rc stuff.

[kkim]

these are the washers FP sends you w/ their jet kits...


3mm washers on the stock needles...


stock needles next to FP needles...


my source of washers used to shim the stock needles...

[tabogon]

Thanks kkim. Will be heading out soon to pick up the right ones.

[kkim]

You're welcome Josh. I wanted to make sure the correct sized washers are used as using too large a washer can cause problems.

[g21-30]

Originally Posted by peter330

Are these the right size. Want to be sure before I order them.

Yes, those are made by Keihin!

[europachris]

Originally Posted by kkim

actually, the 3mm should be the OD.

Here is the washer I used:





3mm OD is going to be way too small.

Chris

[kkim]

Chris,

Any pics of them on the needle?

[tabogon]

Well, I have some #6 washers (roughly 3mm ID) and some 3mm washers that I picked up today. They look to be about the same size, but will let you know if there are any issues with either of them when I get out to the garage.


Apparently they were packaged wrong, because the "3mm" washers are about the same size as the #6 washers and the OD is too big to fit inside the white plastic spring cup. Guess I need to find the closest Radio Shack

[kkim]

I stand corrected. 3mm should refer to the size of the hole in the washer.

The washers Chris pictured are approximately the size that I used, too.

My apologies for the confusion.

some additional washer info...
http://faq.ninja250.org/wiki/Washers_for_carb_needles

[tabogon]

I went and picked up the assorted washers from Radio Shack that noche_caliente recommended and they worked great. So the washers that are needed are either 3mm for metric, or #4 for SAE.

New issue though, I shimmed the carbs, pulled the snorkel and it sounds AMAZING! The revs are a lot more smooth as well. My issue is that before when the bike was warmed up, I would shut the choke and it would idle between 1k-1.5k. Now the bike was idling around 2.5k after everything was done. Do I need to adjust the idle, or did I screw something up?

I used 2x#4 for each carb, and like I said it runs really well, but didn't see anything in either thread pointing out high idle speeds.

[tabogon]

I did nothing but shim and remove the snorkel, didn't see anywhere about adjusting the idle. It did idle at 1.5k-ish after I warmed it up, but after a rev to about 5k to make sure it revved smoothly it hung at 2.5k and stayed there.

Hopefully it will be a little cooler tomorrow, I think it might be a little lean still and will probably throw another shim on it (3 total) and see if that helps.

[tabogon]

Alright alright! So I am thinking that I may have let the bike idle for too long, and with how hot it was outside that may be what caused the high rpm readings. Started it up today after putting the tank back on with the intention of warming it up and adjusting the idle speed knob, but instead it warmed up and idled smoothly and without issue. A quick blip of the throttle and it hung at 2.5k for about 3secs and dropped back down to a nice 1.5k.

So total setup, pulled air restrictor and put 2x#4 washers on each carb.

p.s. Damn is sounds good!!

[Buffalony]

So would it be fair to say: With a straight through exhaust everyone recommends starting with three x 3mm washies. and say start with 2 x 3mm for stock can?

[kkim]

Originally Posted by Buffalony

So would it be fair to say: With a straight through exhaust everyone recommends starting with three x 3mm washies. and say start with 2 x 3mm for stock can?

that should work. don't forget to remove the snorkel as well.

[tabogon]

Well, took if for a 2-3mile test run last night, after a complete warm up it was still idling a bit too high, readjusted the idle at a stop light and ran great.

I am still going nuts on how much easier it is to work on this thing than all the cars and trucks I have ever modded. If I had known it was this easy to play with I would have bought one a long time ago!

[headshrink]

Don't look back man, just be thankful you have discoverd the fun
Welcome aboard!

[sharkie308]

So I'm looking at doing this mod. I'll be removing the snorkle and it already has a very free flowing two brothers slip on. Do you think it would be safe to run 3 washers on it?

[kkim]

Originally Posted by sharkie308

Do you think it would be safe to run 3 washers on it?

yes

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

[headshrink]

I was running 3 washers with snorkle removed and stock pipe/filter, prior to a full jet kit. I was running a little rich, but for me it was a very linear power curve.

[adouglas]

Correct me if I'm wrong, but it'd be safer to run it with three washers than leave it alone. With the stock carb setup it's now way too lean and that's potentially a Bad Thing.

[paydaymayday]

If anyone has trouble finding 3mm washers, head down to your nearest neighbourhood aircraft hangar. That's the good thing about working as a pilot, tons of parts and thousands of tools - and a heated hangar to work in. XD

But in all seriousness, thanks to everyone posting tips and tutorials here. I'm going to try to shim and de-snorkel today, and it's going to be a lot easier with all your guidance

[paydaymayday]

Holy hell, the results are awesome! Here's a few things to clarify the effects for noobs like me:

-the results are tangible. I no longer have to feather the clutch anywhere above 2 mph. That's right, 2 mph. It really doesn't want to stall.

-the results are *really* tangible. It pulls like a bat out of hell now, and I don't have to downshift to accelerate above 60mph - just stay in 6th gear.

-the noise at idle is very similar to stock, but where the difference is really noticeable is when you have 1/2 throttle to WOT below 10k rpm under a load. It makes a beautiful deep growl reminiscent of larger bikes as it breathes in the air.

-if you like to save gas, don't do it. You burn through the juice a fair amount quicker, especially when you're a spirited rider like me.

And a few things I found as I did the procedure:

-set aside 3-4 hours to do it. It took me just under three.

-when people say the carb screws are soft, they are not kidding. I don't know why they make those things out of clay.

-you need really skinny needlenose pliers to get the needles out. They sit deep down in the well, and there's not too much room around them.

Anyway, it was really worth it. What a performance boost - and for free!

[kkim]

[sharkie308]

Can someone give me a quick run down on how to yank the carbs? I have a stripped screw and I really don't want to have to put the snorkle back in. I just want to finish the shim job lol
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[kkim]

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

[sharkie308]

Thanks kKim I'm giving up though. Snorkle is back in. I don't have the time or tools necessary to deal with this. Maybe in a year when I have access to my craftsmen tools. Just wanted to make the bike a lol more user friendly for cindy.
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[kkim]

understand... which is why it is stressed to NOT strip the screws. It makes this job a real PITA when you do.

[Sound Wave]

sharkie, do you have a dremel? if you put a notch in the screw you can use a flat screwdriver to get it out.

[adouglas]

I took my carbs off the bike partly because I wanted to change the pilot jets and pull the mix plug caps more easily, but MOSTLY because I wanted to get better access to those notorious screws.

I bought a brand new, high quality #2 Philips, set the carb down, applied careful pressure and it was EASY.

A very small pop and all 16 of 'em (8 on the caps, 8 on the bowls) came right out.

Seriously, it's worth it to yank the carbs just to eliminate the possibility of messing up the screws.

It also makes it very easy to get the needles out. Just turn the carb over, shake gently, and the diaphragm plus needle just falls out in your hand.

[adouglas]

Originally Posted by kkim

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

I'll add something to that excellent carb removal DIY that isn't mentioned.

There are four big rubber tubes that hold the carb in place. One pair joins the airbox to the carbs, and the other joins the carbs to the engine.

If you take the left-side one that's between the carb and the engine completely out (i.e. remove it entirely from the bike), it's much easier to get the carbs out of the frame.

First you pull the airbox to the rear, to give the carbs some place to go when you pull them back away from the engine. Once they're clear of those forward tubes, you remove the left tube, then rotate the carbs into the space that's now opened up and pull them out through the left side of the frame.

Removing the carbs is much easier than I thought it would be. One of the main reasons for this is that you don't need to disconnect most of the vacuum lines. That'd be a nightmare.

[sharkie308]

Aye. But as someone said up further it really doesn't take much. I barely put any pressure and it sheared right off. On the 2010 it seems the right carb is the harder of the two to get to. The forward right screw is the one that got me. When I get another 6 hrs free I might pull the whole carb and use a good set of pliers to back the screw out.
Posted via Mobile Device

oh and sound wave one of the most frustrating parts is that all my craftsman tools and dremels pretty much anything handy to have are in my storage unit back in fl. Lol

[dubojr1]

Lowe's does carry these for those of you who may be interested. I found them in the Stainless Steel specialty drawers.

http://www.lowes.com/pd_136250-37672...steel%20washer

[Buffalony]

Some tidying up needed here

To everyone havin problems with shearing and anyone reading this thread getting ready to do some shimming....Its not a soft head, its the wrong tool. "You need a JIS phillips bit".

JIS
Commonly found in Japanese equipment. Looks like a Phillips screw, but is designed not to cam out and will, therefore, be damaged by a Phillips screwdriver if it is too tight.

Tip: Use a drywall bit as theyre the perfect JIS substitute and are available at lowes and home depot etc. JIS is not the same as a standard phillips bit. The angles are slightly different to phillips. JIS tools can also be purchased around the net.


Also. Before you attempt this procedure, buy allen-headed machine bolts for replacements. This way you can simply use an allen wrench to access them again in the future.
I bought some from this guy along with everything else I wanted to replace with stainless.
http://www.desmoparts.com/products/p...tm/m5-wellnuts

While your there, purchase anything else you can replace with stainless on your ninjette. Handle bar bolts, muffler end cap, gas cap, etc and never worry about them rusting again!

BTW..He also sell the nylon fairing washers and the actual 3mm washers needed for this mod...in stainless.
His service was awesome and the products were top notch.

Ohh...grab a bunch of well nuts from him while your there too.

enjoy