Kawasaki 08 09 10 Ninja 250 250R Emission Block Off Plate

[kkim]

Originally Posted by afbarr

Am I supposed to pull the rubber boots from the oem airbox and re-use them? Or is there a website I can buy these from (the ones glued to the oem airbox are rather long).

The guy I bought the bike from gave me a dynojet stage 2 kit he never got around to installing but I assume now that the jets in the box are too small for this magnitude of a change to airflow (compared to what was coming through that snorkel thing). The bike has a two brothers vale m2 exhaust system (slip on). According to the the dynojet chart they recommend 98 (dynojet size -- not sure what the equivalent Keihin size is). The box included a pair of 100s too (again, not sure what the Keihin equivalent is).

I looked at the jetting database but it's all over the place with conflicting sizes (even with the same brand of jet and setup). I was thinking of ordering (authenitic) Keihin jets in pairs of 110, 112 and 115 -- am I likely to find the optimal jet in this range for my set up? I saw someone recommended jetsrus.com so I'll check them out.

I'm using the intake boots from the stock airbox.



buy some larger main jets equivalent to Keihin 110 or 112s. You may need to go up or down later according to your needs, but that's a good starting point.

[afbarr]

Do I need to drill anything for installing bigger Keihin 110+ main jets?

[indr]

kkim, what are you using for the crankcase breather with that k&n setup?

[kkim]

Originally Posted by afbarr

Do I need to drill anything for installing bigger Keihin 110+ main jets?

no, just replace the main jets you have in there now.

[kkim]

Originally Posted by indrish

kkim, what are you using for the crankcase breather with that k&n setup?

an old fuel filter I had in my toolbox crap drawer when I was doing the airbox delete. never went back to replace it.

[rwheelz]

I bought a $9.99 breather filter at O'Reilly's (universal). It didn't quite fit the crankcase hold, so I dremeled it out and it fit fine.

[afbarr]

Originally Posted by kkim

no, just replace the main jets you have in there now.

Sorry I just realized where I read about drilling -- that was from the dynojet kit which says to drill out the fuel mixture screw plugs so you can set the underlying screws at 3 turns outs.

So I am a little confused -- it looks like there are 4 parts involved with the "main" jet:

(1) the "needle"
(2) the "needle jet" (small brass cylinder part that just slips over needle)
(3) the "needle jet holder" (sits on top of the needle jet and screws in to carb)
(4) the "main jet" (screws into needle jet holder)

Looking at the dynojet kit, for each carb, it has one needle and several main jets (94, 96, 98, 100). I.e, it supplies parts (1) and (4) above only [not parts (3) and (4)]. Well, that and some small clips and washers.

So my question is this: if I want to "build my own jet kit", does that mean I just need to buy a "needle" and "main jet" [parts (1) and (4) above] Or do I also need to buy parts (2) and (3). If so, why does dynojet not supply them. Judging from what supplied in the dynojet kit, it seems like the OEM parts (2) and (3) can be re-used for different size needles and main jets? But the dynojet kit came with one needle which can work with the 4 different main jets they supply (94-100). Why didn't it come with 4 needles instead of just one? Or why didn;t it just reuse the OEM needle?

Basically, if I pick up 110, 112 and 115 Keihin "main jets", do I need to buy a needle (or needles) as well? What about the "needle jet" [part (2) above] and "needle jet holder" [part (3) above]?

Apologies for my confusion.

[kkim]

what you are paying for in a jet kit are the proprietary needles that they supply. They are not OEM type needles and companies source their needles according to how they want the bike to run. The pilots and main jets you get can be purchased from any place that sells Keihin jets.

have you read these on rejetting your bike?

http://faq.ninja250.org/wiki/I_want_...uretor_jetting

you'll find the needles that come with our bikes are lean from the factory (in addition to being different left and right). selecting your own needles would require a lot of guess work/R&D which the jet kit companies have already done for you in selecting their needles.

[indr]

Shimming w/ washers would be cheaper than buying new needles/jet kits no?

[kkim]

yes, but not as accurate or nearly as adjustable.

[indr]

Sandpaper + micrometer

[kkim]

Originally Posted by indrish

Sandpaper + micrometer

go for it. let us know how that turns out for ya.

[afbarr]

Originally Posted by kkim

what you are paying for in a jet kit are the proprietary needles that they supply. They are not OEM type needles and companies source their needles according to how they want the bike to run. The pilots and main jets you get can be purchased from any place that sells Keihin jets.
...
you'll find the needles that come with our bikes are lean from the factory (in addition to being different left and right). selecting your own needles would require a lot of guess work/R&D which the jet kit companies have already done for you in selecting their needles.

Ahh, I didn't know that about the needles. Makes sense now why they supply their own needle. I sent Dynojet an email and explained my setup and just asked them what they would recommend. The biggest main jet they provide is a 100. I have a feeling I'll need a bigger main jet.

I need to learn more about carbs... I'll check out the site you recommended.

[kkim]

Originally Posted by afbarr

I have a feeling I'll need a bigger main jet.

if you have removed the airbox and are using pods/open filter, yes you will. look at Factory pro and the kit they have for bikes w/o an airbox. use the jets sizes they supply and cross reference the Dynojet sizes for jets you should purchase for use.

[afbarr]

Originally Posted by kkim

if you have removed the airbox and are using pods/open filter, yes you will. look at Factory pro and the kit they have for bikes w/o an airbox. use the jets sizes they supply and cross reference the Dynojet sizes for jets you should purchase for use.

I've only found conversion charts for Keihin <--> Dynojet <--> Mikuni. I have not seen a FactoryPro comparison against any of the above. I guess I could pick up the Keihin equivalent of Dynojet 102 and up (since I already have Dynojet 100).

[headshrink]

Originally Posted by afbarr

I've only found conversion charts for Keihin <--> Dynojet <--> Mikuni. I have not seen a FactoryPro comparison against any of the above. I guess I could pick up the Keihin equivalent of Dynojet 102 and up (since I already have Dynojet 100).

I already made the mistake of making this assumption. FP size codes = Keihin size codes. Source = FP.

[kkim]

Originally Posted by headshrink

I already made the mistake of making this assumption. FP size codes = Keihin size codes. Source = FP.

yes, FP and Keihin use the same numbering system for their jets.

[afbarr]

Well, I could just not install the Dynojet stage 2 kit (that was given to me) and instead just pick up some 110 and 112 Keihin main jets from jetsrus. If so, would I just use the stock needle and main jet holder that came with the cvk30 from the factory?

Or does using the Dynajet or FactoryPro needle with the Dynojet or FactoryPro main jets really make that big of a difference compared to equivalent main jet sizes from Keihin?

Is the "big deal" about the Dynojet kit the fact you get a proprietary needle with grooves that makes it easy to "shim" up or down with an e-clip?

[kkim]

The big deal about any aftermarket jet kit is the selection (taper) of the needles they provide/select, which control the fuel flow to improve (richen) midrange performance, which a stock bike lacks.

yes, you can use the proper/equivalent Keihin main jets w/ your DJ needles.

[afbarr]

Originally Posted by kkim

The big deal about any aftermarket jet kit is the selection (taper) of the needles they provide/select, which control the fuel flow to improve (richen) midrange performance, which a stock bike lacks.

yes, you can use the proper/equivalent Keihin main jets w/ your DJ needles.

Ok, so I ordered 108, 110, 112 and 115 keihin main jets from Jetsrus. Hopefully one of these will be optimal.

[kkim]

from what we've experienced, those should cover the range you'll need to properly jet the mains.

[afbarr]

Originally Posted by kkim

from what we've experienced, those should cover the range you'll need to properly jet the mains.

I hope so as the price of buying these in pairs for a range of sizes adds up I appreciate all your help with info. I am a little worried about the amount of work required to find the right main jet and needle height but I guess you have to pay the piper one way or another if you want to help the engine breath a little better and get better throttle response.

I also ordered the uni 104 filter for the crankcase breather vent. The block off plate arrived on Friday! and I installed it yesterday.

I think half of the reason I'm doing all this is to just simplify the morass of tubing underneath the tank! let alone try to improve performance a little.

[kkim]

Aaron,

I can assure you, once you get the engine tuned properly, the money invested to do so will seem inconsequential. Yes, it may cost a few bucks to get to that point, but the knowledge and understanding you gain of what those little pieces do inside the carbs and how they improve the engine output is priceless.

[sharky nrk]

That does look alot cleaner

[afbarr]

Originally Posted by kkim

Aaron,

I can assure you, once you get the engine tuned properly, the money invested to do so will seem inconsequential. Yes, it may cost a few bucks to get to that point, but the knowledge and understanding you gain of what those little pieces do inside the carbs and how they improve the engine output is priceless.

So installed the dynojet needle last night. I am waiting on the Keihin main jets to arrive from jetsrus. Looking at the factory pro "how to tune a carb" page: http://www.factorypro.com/tech/carbtun.html, I see that the very FIRST step is to find the best main jet. Then SECOND step is to find the right needle height. BUT you have to select a needle height whether you want to or not in order to do the first step. So what needle height should you use to during the first step?

I assume you want the tip of the needle to be as far away from the main jet as possible?

When I installed the dynojet needle I think I did the opposite (I didn't think about this until today). I put the e-clip at the first notch at the top of the needle (the bluntest end of the needle opposite the main jet side). I also stacked the two washers on top of the needle assembly/diaphram (inside the white plastic spring cup).

Was I supposed to place the eclip as far down the needle (toward the pointy end) as possible? This makes sense to me but I just want to verify with the more carburetor tuning savvy folk here Do I use the washers at all when doing this?

[kkim]

http://faq.ninja250.org/wiki/How_to_...e_your_jetting

once you select the proper main, start with the e-clip in the middle position on the needle, then work from there.

FP needles next to stock needles... e-clip on FP needle on the 3rd clip position w/ washers stacked above it.

[afbarr]

Ahh... so you sandwich the washers between the e-clips? That makes sense now I will move the eclip to the third notch and place the washers on top and then put the second eclip on top of them. Do the washers act as spacers or as weight? I will read the link you sent. I also order the Haynes Fuel Systems book and that should arrive soon

Thanks for your help!

[headshrink]

Deleted due to redundancy.... Kelly said it better.

[kkim]

Originally Posted by afbarr

Do the washers act as spacers or as weight?

The washers above the e-clip are supposed to act as weights on the needle to keep it from vibrating and shifting up and down while the bike is running. Dunno how true that is, but that is what the aftermarket jet kit makers recommend so I went with it as per their directions.

[headshrink]

Originally Posted by kkim

The washers above the e-clip are supposed to act as weights on the needle to keep it from vibrating and shifting up and down while the bike is running. Dunno how true that is, but that is what the aftermarket jet kit makers recommend so I went with it as per their directions.

Kelly,

I have never really done this. Could it be possible that fixing that might solve my phantom surge?

[kkim]

Originally Posted by headshrink

Kelly,

I have never really done this. Could it be possible that fixing that might solve my phantom surge?

try it... it might.

why is it you never did this? it's in your installation instructions for the jet kit, right?

[headshrink]

Originally Posted by kkim

try it... it might.

why is it you never did this? it's in your installation instructions for the jet kit, right?

I just checked... I might have missed it, but I didn't see it. I have known it is done, but since I have never been fully satisfied with my tunning, haven't locked the needle down. Think I might just spring for a dyno run....

[kkim]

Bob, I just looked at the installation instructions on FP website and can't find any reference of installing washers above the clip. I did find the washer comment in the Dynojet instructions, so that's where I must have picked up the tip.

http://www.dynojet.com/pdf/2193.pdf

BTW, FP needs to work on their website... it sucks.

Interesting tidbit from FP website... says that they no longer sell jet kits to people in California due to emissions.
http://www.factorypro.com/Prod_Pages/indexmake.html

[headshrink]

Originally Posted by kkim

BTW, FP needs to work on their website... it sucks.

Interesting tidbit from FP website... says that they no longer sell jet kits to people in California due to emissions.
http://www.factorypro.com/Prod_Pages/indexmake.html

You are right about the website.

The whole CA issue is merely a "wink, wink" thing. They are after all located in CA, and are busy supplying jet kits for all our TRACK and OFF ROAD bikes (ask me how I know).

[natek]

anyone worked with Little Red Ninjette before? found the same plate for a few bucks cheaper.

http://shop.littleredninjette.com/Sl...SSBlockOff.htm

does this hurt engine life or anything?

[Momaru]

Originally Posted by natek

anyone worked with Little Red Ninjette before? found the same plate for a few bucks cheaper.

http://shop.littleredninjette.com/Sl...SSBlockOff.htm

does this hurt engine life or anything?

Not that any of us have noticed.
Never heard of LittleRedNinjette though, looks like a nice small shop. I'd check the total + shipping cost though. Might save w/ the bigger company on total cost.

[headshrink]

Looks like a good collection of stuff. One thing that makes me uneasy, however, is that there seems to be no way to contact them, and no indication as to their location.

[natek]

Originally Posted by headshrink

Looks like a good collection of stuff. One thing that makes me uneasy, however, is that there seems to be no way to contact them, and no indication as to their location.

yeah that was the 1st thing i looked for.

[headshrink]

This is the sole reason I won't give them my business; might as well go with Shinto in that case... (refering to a giant bucket of worms).

[cuz]

can you still dyno w/out it? like get a perfect reading.