DIY Shimming the carb needles.

[pilotgeorge747]

Your tank isn't full and leaking out the overflow hose underneath the bike is it? I'm thinking if the carbs aren't sealed properly and leaking gas that you would be experiencing some performance/engine issues as well and not just gas leaking.

[EthioKnight]

Shimming can be a PITA at first...I was screaming bloody murder at the freaking tubes crisscrossing over the left carb. I'm seriously considering doing the kleen air delete just to get those rubbery snakes from hell out of my bike!
But yeah, shimming (w/ 2 washers and a snorkel removal) definitely smoothed out my low end. I also took it up to 100mph (indicated) just to test if it had any negative impact on acceleration and top-end, all went well for me and I'd recommend it to any one, especially those with slip-ons.

[Mr.E]

Originally Posted by pilotgeorge747

Your tank isn't full and leaking out the overflow hose underneath the bike is it? I'm thinking if the carbs aren't sealed properly and leaking gas that you would be experiencing some performance/engine issues as well and not just gas leaking.

I thought it was originally but my tank is only half full

I remember that was what the issue was when we first did it. But idk.

[headshrink]

Originally Posted by Mr.E

I thought it was originally but my tank is only half full

I remember that was what the issue was when we first did it. But idk.

Double check your fuel lines and fittings too. Also, this may be a long-shot, but make sure your petcock wasn't damaged when you removed the tank, or the matting surface between petcock and tank for that matter. Of course make sure it is also on [strikethrough]Prime[/strikethrough] "ON".

[pilotgeorge747]

BTW have you double checked that the Petcock is on the "On" position and not the "Prime" position? Just was a quick thought.

[headshrink]

Originally Posted by pilotgeorge747

BTW have you double checked that the Petcock is on the "On" position and not the "Prime" position? Just was a quick thought.

I can't believe I said that! Yes, the ON position is correct. I really shouldn't trouble-shoot mechanics while at work.

[Mr.E]

Lol i was about to say omg no its on the on position last time i checked! lol. Yeah, its on "on". :-\ its not a consistant leaking though, only every once and a while, that i can see anyways.

[Buffalony]

2 washers, snorkel removal, carb balance screwed my bike up. Doesnt pull for sh!t and turned it into a gas hog at the same time? I'm gonna take a washer out this spring. If that doesnt work I'm going back to stock because it screamed then.

[choneofakind]

sounds like a good idea Buffalony. 1 washer might be better. Who knows, you might even be one of the lucky guys who doesn't need raised needles without the snorkel??

[Slono]

Do I still have to shim if I have a jet kit? I have a main jet, but I don't think I have washers.

[headshrink]

Originally Posted by Slono

Do I still have to shim if I have a jet kit? I have a main jet, but I don't think I have washers.

Usually. Shiming, to raise the needle, addresses the mixture in the mid-rande, where the main jet is at the high end.

[Steven250R]

Hey guys,

So i put a full exhaust system (PLMFG) i know some of you guys arent big fans but it was in my price budget. Anyways when im crusing around in the 3-6krpm range it kind of bogs out and i have to get it more gas which also takes a second to pick up. I know i should be looking into getting a jet kit but im really not trying to put more money into the bike and im not that confident in taking apart my carbs and i know i cant afford taking it to a shop. So im hoping for some advice from you guys/girls that have done this mod with a similar setup as mine.

I've got my bike all torn apart just need to remove the carb covers, pull the needles,throw some washers on( use #4 washers which i got from the assorted bag at radio-shack), MAYBE pull the snorkel and reassemble.

So my question is, has anyone had success with 3shims, pull snorkel and full exhaust? I just dont want any dead spots in my powerband without having to get a jetkit.

BTW im located in the Bay Area i believe my elevation can range from 300ft-1000ft?

Thanks!
Steven

[choneofakind]

buy the next size larger jet from a dealership or jetsrus.com, and experiment with which main jet feels better. Then test needle height by adding one washer at a time.

We aren't going to be able to tell you which jetting setup is correct out of the box. You're going to have to test it for yourself.

The jetting database is a good idea of where to expect your jetting setup to end up, but it's just a starting place. Test-riding is still mandatory for jetting.

[Steven250R]

Just finished up.

Threw in 3 washers and pulled snorkel.

Runs alot better then it did with the full exhaust and stock carb setting, alot.

Installation was pretty easy and only cost me $3!

Low end throttle response is alot better forsure. Might be doing the zip-tie mod next! Anyways thanks for all the help this forum has given me.

[Tay]

Hey all,

I'm from Australia, have a 2011 Ninja 250.

Just came back from a nice run on the freeway

Was a bit hesitent to do this, had a few hours to spare today, went to my local JayCar electronics store and got a pack of 25 3mm stainless steel flat washers for $3. Then to my local Supercheap Auto store to get one of those small ratchet bit sets for $15, it came with assorted bit sets, I used the #2 Phillips bit. Highly recommend this as it makes removing the carb screws a breeze, just some pressure on the head and slowly turn, didn't damage any

My bike is one of those lucky ones that was tuned correctly from factory, never had any issues with what some of you are having. A month ago I installed a cheap DanMoto slip on muffler to get some sound.

I ended up using 2 washers per needle, while I was there I removed the snorkel and the Kleen system as well

Definitely a huge improvement, pretty much the same as everyone else is experiencing, it's like a new bike, on the freeway run, went through 2nd and 3rd gear to redline, it was very nice.

Followed the DIY guides and had no issues, it was my first time getting the bike naked for this job, didn't use a bike stand, just the kick stand, removing the tank was a breeze as well, this is a one man job.

My 2 cents.

[choneofakind]

Welcome Tay!! Glad you enjoy how the bike feels with some carb changes!

Hey, random question, I want to replace my carb cover screws. Does anyone know the exact dimensions of the screws so I can replace them with allen head screws?

[choneofakind]

M4x16 screws. stainless steel so they don't rust

Originally Posted by choneofakind

M4x16 screws. stainless steel so they don't rust

Haha you are just so helpful Thank you sir

[choneofakind]

I also have no life since my hw is done. I gotta stay connected with my ninjette somehow since I can't ride it.

lots of daydreaming and forum time.

Haha I'm procrastinating homework right now. No class tomorrow so I'll do it then...

[edxmon]

Are the washers supposed to fit inside the 4 pronged plastic "thing" that goes on the spring that holds the diaphragm down? I've only had my bike for about a month, and I've only ridden in in small 5-10 mile trips but I've already gone through about half a tank and I don't think I've done more than 75miles. My exhaust IS smellier than before and makes me thing I'm running way rich.

Now that I think about it, the four pronged thing holds down the inner cylinder of the diaphragm, inside of which the needle sits.

I guess even if I am running rich, once I get my Danmoto slip on it'll lean it out a bit.

[Pudge Ate Me]

I just shimmed my needles by 1.5mm per needle (3 washers, they were only .5mm thick per) I have removed the snorkle, have an MGP Growler slip on and a K&N air filter (stock airbox).

Anyway, it was raining today so I just road for about 5 minutes. Things I've noticed so far:

Full choke when warm idles at a wopping 7k rpm ( but no choke idles right at 1.4k) Is that a little bizzare or is that correct?

The throttle seems more responsive and I don't hear any backfire from the slip on anymore. Is this what I should be expecting?

[choneofakind]

Originally Posted by Pudge Ate Me

Full choke when warm idles at a wopping 7k rpm ( but no choke idles right at 1.4k) Is that a little bizzare or is that correct?

so only use partial choke. It's not an on/off switch.

Originally Posted by Pudge Ate Me

The throttle seems more responsive and I don't hear any backfire from the slip on anymore. Is this what I should be expecting?

Yes that sounds right

[sherwiner]

If you put the washers on the needles, how do you get the needle back in without the washers falling down into the diaphragm?

Sherwin

[pilotgeorge747]

Originally Posted by sherwiner

If you put the washers on the needles, how do you get the needle back in without the washers falling down into the diaphragm?

Sherwin

Magnet or tweezers.

[edxmon]

Originally Posted by sherwiner

If you put the washers on the needles, how do you get the needle back in without the washers falling down into the diaphragm?

Sherwin

You can also use Vaseline to stick the washers to each other and the head of the needle

[Deadly Ninja]

Hey all! I'm new to this world of sport bike. Just got my 2010 ninja 250 a month ago. Did the shimming, stripped the screw, but got it out and replaced it with allen screws. I currently have 2 3mm washers under each of the needle. The bike has full Carbon Yoshimura Exhaust, OEM airbox, snorkel removed and a k&n air filter. The bike runs excellent. However, on occasion while cruising at about 6-8k rpm on 3rd or 4th gears, the bike sometimes "miss fire'. IDK how to describe it, its almost like the bike drop in rpm like maybe 500-1000 then get back to the original crusing rpm (all this happen without the throttle being manipulated). Does that mean theres something wrong with it ? I haven't remove the Kleen air system yet, do you guys think it would solve this problem with that system remove? Sorry for the noob question

[THE BIG SITT]

Is the filter clean? How's the oil? I'd start there.

[Deadly Ninja]

The oil has been changed 400 miles ago. The bike currently has 2k miles, I used Mobil 4T synthetic motorcycle oil. And the k&n filter is brand new . Got it 2 weeks ago. Should I change the spark plugs?

[rainking]

Another satisfied customer! Thanks OP!

Let me say that I've own an 06 500r, 06 zx6r, 06 zx10 and currently also an 08 zx10r so I've had my share of motorcycles. I recently picked up the 2009 250r to have with my 08 zx10r. After being spoiled with FI, you learn to hate the choke and waiting for the bike to really warm up. The 250 takes FOREVER to warm up. It bogs down really bad in the lower range. I put a danmoto exhaust and that made it worst. I knew I had to either jet or shim the needles. I took the time to read all the post here so I was prepared. I'm use to wrenching my own bikes and have replaced throttle bodies, installed power commanders, sprockets etc. in the past. All in all, it went good. Only hiccup was I initial forgot to hook the bracket for the choke so the choke was non-functional. Good thing I didn't hook anything back up yet besides the gas line to start her up. I didn't take front fairings off as I didn't see that it was necessary. I used two #4 radio shack washers on each needle and used vaseline to hold them in place. I used a regular deWalt #2 philips head and my 1/4" ratchet. Used a lot of downward force when turning and didn't have any issues with stripping. The job took me about 1 1/2 hours. I'm also +1 with my front sprocket Between these two mods, it has completely transformed the ride-ability of this bike especially in the lower gears / mid range.

I bought the bike stock and so far I have installed the danmoto exhaust, shogun frame sliders, +1 front sprocket and now this. She's finally rides the way I want her too.

I know, everyone loves pictures so here you go. Snapped a few.









Don't want to get the zx10r jealous!

[geeker]

Originally Posted by rainking

Another satisfied customer! Thanks OP!

I never thought to use a 1/4" ratchet on this. I bought a long-shaft #2 phillips screw driver for the task. Put a bit of downward pressure on the handle with the palm of my hand, and then gave it a light smack with my other fist before turning. It's worked every time for me. A magnetic pickup tool is nice to have while doing this. It makes removing and replacing the screws and washers much easier.

[jenndiggity]

Does it make a difference if the washers are steel or brass?

[chrislols]

I recently put on a Dan Moto exhaust and before anything, it would take a LONG time to warm up otherwise it would cough and spit and stall.

Full choke would be 4k rpms. Today I tried shimming, 2x #4 washers on each side and full choke was 5k RPM. It still took long to warm up and felt like it was bogging down.

I ended up removing the snorkel, and while it was much more louder and rumbling, I still needed choke to even get up a 5 degree increase in my driveway to pull in.

I ended up putting a 3rd washer, and it still takes a W H I L E to warm up, maybe even longer, but when riding and I kicked it into second, it shot up to like 8k and I had to calm down, almost as if it's running MUCH MUCH MORE SMOOTHER, as well as leaner, the sound and the engine just flowwws sooo well.

But idling it just sounds like it's onoffonoff, and if you TOUCH the throttle it'll stall. Even warmed up and sitting in first, it sounds like it skips every few beats.

What do Ninjette?

[geeker]

It will need choke to start when cold. Whether it's rejetted, shimmed, or stock. It's the nature of the beast. Are you snapping the throttle open, or just rolling on more throttle?

[chrislols]

Today I still didn't get a chance to ride it, but I started it and completely cold it just spit and sputter, it wouldn't even start without the choke on. What should I do? This can't be right
Posted via Mobile Device

[geeker]

Originally Posted by chrislols

Today I still didn't get a chance to ride it, but I started it and completely cold it just spit and sputter, it wouldn't even start without the choke on. What should I do? This can't be right
Posted via Mobile Device

If it doesn't ride well after warming up, it's probably not right. What is right is using the choke when you start a cold engine.

[edxmon]

Originally Posted by geeker

If it doesn't ride well after warming up, it's probably not right. What is right is using the choke when you start a cold engine.

THIS.

I don't know why people are scared of using the choke, it's there for a reason: TO BE USED.

My cousin has a Virago 250 and has spent hundreds of dollars taking it to shops because it won't stay running when it's cold-started, unless you use the choke.

[jenndiggity]

just shimmed and putting hoses back together under fuel tank, but cannot determine what hose goes in the very center of the top of carburator??? The overflow hose that is connected to the back of the fuel tank goes nowhere?

[geeker]

Originally Posted by jenndiggity

just shimmed and putting hoses back together under fuel tank, but cannot determine what hose goes in the very center of the top of carburator??? The overflow hose that is connected to the back of the fuel tank goes nowhere?

I never watched which hose went where on the carbereturs so I can't help there. Maybe this screen shot from the manual will help? I highlighted the text that accompanies the petcock in figure 3.