Tuning Tips For EFI Bikes ?
 

Hi. Great forum. Learnt so much about general maintenance already from here.

Are there any resources here about tuning EFI'ed bikes ?

My KLX250S is an efi bike (asian country). Most of the resource here concerns the carb'ed bikes.

Have just removed the air box lid and it totally woke up the bike. Nice growl too. Any impact on the EFI ? Fuel / air ratio ?

Thanks.

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The Americans and Australians get the carbed bikes, in Europe, Asia and South America, we get the EFI.

There are a few options for tuning. The most efficient way and the best bang for your buck is to up the displacement with a bigbore kit.

1) Get a bored cylinder, piston + gasket
2) Get a EFI piggyback controller.

For cylinder you can go with OEM Kawasaki 292cc cylinder, Kustom Kraft 331ccm cylinder or one of Bill Blues cylinders (Various sizes up to 351cc).

Be ware that nobody has attempted to go over 331cc on a EFI KLX with documented success yet. Does not mean its not possible however. Maybe you will be the first? :P

For piggyback controller either use Dobeck Performance Electronic Jet Kit(EJK) (Which I use) or Powercommander V + Autotune (More expensive, but more precise). Its also possible that some of the people with the Powercommander will share maps with you.

There are also some Thai piggybacks, but they are poorly translated to English and difficult to use for anyone but Thais, so there isnt much info on them on these forums.

Lastly, you can get a slip-on exhaust. Does not really add that much, but it opens the whole thing up a bit. I got an FMF Q4, which is one of the quiet exhausts on the market. Its still MUCH louder than stock. So keep that in mind when you order an exhaust.

Better airfilter
Bigger Snorkel from KDX200 or removal of airbox lid maybe also give a bit.

I myself run a 292cc OEM Kawasaki cylinder + Dobeck EJK controller. It runs really good when I ride it well, but its slightly choppy at low throttle. Not a big problem. The EJK is much easier to set up than the PCV. The EJK is also cheaper than PCV + Autotune, but if I had the money I would go with the PCV. If you can get access to a guy who knows how to operate a dyno well, you do not need to buy the autotune. He can make a perfect custom map for you, but you shouldnt let anyone do this.

There are also better cams out for the bike. Webcams 101 are a popular choice. They will add more pull after 8000rpm.

Also dont neglect suspension, stock suspension on the bike is kinda mushy :)

Isn't there a free mod for the clutch switch that allows the bike to go above the cut off speed? or something like that.

Found it.

super-simple way to derestrict Kawa 250 single (?))

thanks guys

Why more rpm's? Its a single cylinder bike.... maybe you got the wrong bike.

Maybe this can help...... https://www.kawasakiforums.com/forum...x250-uk-40661/

+1 on zl PINHEAD lz link. That link has some quick reference good info on EFi tuning.

If you want to know just about everything about EFi tuning. Find a comfortable chair, get some snacks/drinks & prepare for a long read!! :cool:

https://www.kawasakiforums.com/forum...250-efi-35678/

i read that link. i dont agree with the necessity for an o2 eliminator for just an intake mod or a slip on.

the efi will accomodate. Full system will need mapping though.

thats my understanding

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I respectfully disagree with you on this. In my experience with the klx the only reason there is a 02 sensor on the bike is to accommodate the Euro3 & EPA emission compliance & to keep the anemic stock bike running dangerously lean to pass there ridiculously tough tests.

Every fuel controller available for the klx comes with an 02 sensor eliminator to stop the ECU & 02 narrow band sensor fighting with the fuel controller & stop them continually trying to lean off the AFR to 14.7 or so.

I got a Bosch wide band 02 sensor on my bike & can view my AFR accurately in real time on the PCv. My bike is at it's most powerful with a 13.4 in the low rpms rising to 12.8 AFR in the upper rev range. This is not possible without the 02 eliminator fitted & it only costs about 30 bucks to buy separately. :cool:

Please get a garage to stick a gas analyzer in your exhaust before after fitting just an intake mod or a slip on & tell me your air fuel ratio. This would be interesting info for everyone to learn.