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Big bore kit on klx250 2009 EFI

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Has anybody put a big bore kit on klx250 2009 EFI ?

(talking about the injection model)

Thanks

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It's the same engine patrioti ! I had ( and still have ) a klx250es , great bike !

As far as i know the engine is the same , the only difference is carb vs injection . I had drove a d-tracker 300cc from a buddy and the difference in power was noticeable !

Also i believe the more reliable kit is the oem 300 cylinder + piston from Kawasaki .

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I know that is the same engine.

the difference as you say is carb vs injection.

THATS A BIG DIFFERENCE

Because since you put 50 or 80 or 100 cc more air into the cylinder

you need more fuel to mantain fuel-air ratio.

In carb models you rejet the carb to achieve this.

In 2009 EFI model would the injection adjust or you gonna end up

with problems due to lean air mixture.

Thats why i need information from people they have installed a big bore kit

on 2009 EFI model to find out if it worked OK

Thanks anyway

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stratosa, your point is more than valid. I think that the EFI would automatically correct because having a bigger cylinder is just like the smaller one revving faster. Top end is the only place a problem could arrise, I'm not sure if the EFI uses ratios to keep the mix right or if its preset for the > rpm + elevation + intake.

Good luck finding out more! :doh:

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Dear visbits allow me to desagree.

Having a bigger cylinder is NOT just like the smaller one revving faster

EFI must inject more fuel to mantain the correct fuel-air ratio.

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The MAF (Mass air flow) sensor should be able to read the air going in and provide the correct amounts of fuel.

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Usually when you do a big bore ( at least to drz's ) you have to go down a # of main jet , if you have 160 main usually you go down to 155-158 .

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Usually when you do a big bore ( at least to drz's ) you have to go down a # of main jet , if you have 160 main usually you go down to 155-158 .

Were talking fuel injection bud :doh:

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Dear visbits you may be right. The MAF (Mass air flow) sensor should be able to read the air going in and provide the correct amounts of fuel.

(Can supply 40% more if you install a350cc kit) ?

On the other hand i remove the airbox lid, more air should go to the cylinder and more fuel must provided from MAF but i did not see any difference.

Thats why i made this post to find out a fellow rider who has installed already

a big bore on klx250 2009 EFI to tell me his experience.

Thanks anyway

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There is not even one person in the whole world who has istalled a big bore kit on klx250 2009 EFI ?

(talking about the injection model)

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The controller will probably try to correct for the higher flow. The question is whether it is capable of it and if the injector will flow enough.

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For all these reasons you describe i am looking someone who has already istalled a big bore kit on klx250 2009 EFI (injection model) to share with us his experience

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Hello Stratosa,

I have no personal experience with big bore on an EFI KLX, but there's a company in Japan called BLR who should be putting out an aftermarket controller for the EFI D-tracker/KLX250 by the end of July.

The reps from BLR said they tried using a KLX300 cylinder on their test bike, but kept getting an 'FI' warning light, both with the ECU in stock configuration and with their controller hooked-up.

They didn't go into specifics of why the light was coming on, but maybe the injector is the limiting factor...just a guess though.

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OK, I spoke to soon. Here's an update on big bore combined with EFI. BLR seems to have solved the earlier problems it had with the big bore kits.

They have made some F/A curves that will allow the controller to work with big bore kits ranging from 292-315cc. The the higher number is 315cc because that is the highest displacement large bore kit offered here in Japan. My guess is it will work with the 331, but somebody would have to be the guinea pig. :crazy:

Should be an absolute fire breather combining EFI with the 315 kit though. I'm guessing 30hp without any mods to the head.

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haha doesnt look like it

i didnt no there was an efi model klx?? haha other wise i would have gotten it

how much more is it then ur carbed klx?

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haha doesnt look like it

i didnt no there was an efi model klx?? haha other wise i would have gotten it

how much more is it then ur carbed klx?

About the same price, but don't worry about it, because it's not available in the states.

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Here's the latest update on big bore for the EFI KLX250S...which means this info is not for people who live in the USA, AUS or Canada.

The company developing the controller (BLR) said they ran the stock injector with a large bore cylinder (292cc)and the bike wouldn't start or idle properly..they said the injector is the limiting factor, so I wouldn't go bolting a large bore kit onto your EFI KLX at this time.

They are developing a 'kit' for large bore cylinders (292 -315cc..I image 331 would also be OK), which includes a controller and a suitable injector. Since it took them over a year to develope the controller for stock displacement, I wouldn't hold my breath very long...although anything is possible. :thumbsup:

They will have a contoller and harness available for STOCK DISPLACEMENT engines at the end of July.

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I am doing an install right now - Kustom Kraft 300 cylinder bored to 331. I can not get it to run yet. It will idle then die when you give it any throttle. I've ordered the Kawasaki Programmer and should have it any day now. I also bought the Web Cams 101 package but pulled them out tonight and went back stock to make sure that wasn't the problem. The results were the same.

I believe it's definitely in want of more fuel. If I had more details on the fuel injector then I could just put a larger injector in place and probably make it work but it's a lot cleaner to change the fuel map.

I live in Indonesia - Balikpapan and watch this Forum looking for information. The KLX 250s is a nice machine but until some after market programmers are available it is an expensive option to go the route I have.

Pete

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I wish you the best.!!!

If you suceed you are going to be the first person in the world who manage to install a big bore kit on KLX250 EFI. Please keep us informed.

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I believe it's definitely in want of more fuel. If I had more details on the fuel injector then I could just put a larger injector in place and probably make it work but it's a lot cleaner to change the fuel map.

Pete

If you find the right injectors diameter is cleaner and simpler than anything else. The right injectors diameter comes from the equation:

New cylynder or piston diameter /(divided) to old cylynder or piston diameter

* (times) old injectors diameter.

The result will give you the new injectors diameter you are looking for.

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