How to soup up KLX250 EFI the easy way

Svendura · Derestricted Danger Joined: 04 Jan 2012 Karma :

I've got myself a brandnew Kawasaki KLX250 2009 EFI and I love it
because it's light and nimble though it could use a little more power.

I am not into loud pipes or other illegal stuff, but there is an easy
way to push a little more life into the small 250cc power plant. The
costs will be no more than 10p and it is absolutely easy done. Let me
show you how.

https://pic.endurowandern.eu/klx_tuning.jpg

The engine is limited in higher revs and doesn't rev much higher than
approximatebly 7.500 rpm. This way the max speed won't exceed
105 km/h (65 mph).

But Kawasaki provides the bike with a second and well hidden ignition
curve. Once you activate that power curve, the KLX does 130 km/h
(80 mph) and is much more fun to ride.

The power curve is activated by bridging the switch at the handlebar
next to the clutch lever. The pics should show you the details.

Step 1: find the switch.

https://pic.endurowandern.eu/Kawa-frisieren-pic1.jpg

https://pic.endurowandern.eu/Kawa-frisieren-pic2.jpg

Step 2: Remove the black flat connector.

Careful: Don't use a tong, you won't need it and might damage the
connector. Leave the small tongues alone, that I've marked with an
X. Instead there is a small latch on the underside of the connector.
Once you press it in, you can remove the plug easily.

https://pic.endurowandern.eu/Kawa-frisieren-pic3.jpg

Step 3: Make a short cable bridge of 40mm length and 1.5mm diameter
and strip of 10mm at both ends.

https://pic.endurowandern.eu/Kawa-frisieren-pic4.jpg

Step 4: Plug both ends of the cable into the black flat connector
that you've unplugged in step 2. When you need a little presure to
press it in, you've chosen the right diameter.

https://pic.endurowandern.eu/Kawa-frisieren-pic5.jpg

Step 5: Ready. Have fun.

https://pic.endurowandern.eu/Kawa-frisieren-pic7b.jpg

I've plugged the connector upside down on the small latch, so that it
doesn't flow in the wind. Whenever you want to restore original
condition, just rip the cable off and plug the connector back where it
belongs. No tools needed.

I have now ridden 13.000 km on the KLX mostly with holliday
luggage and I've not seen any side effects except having more fun.
Fuel consumption has risen a tiny wee, but no more than I am going
faster now.

Of course this works only with the fuel injected models of KLX250,
make 2009 and up.

https://www.svendura.de/pic/gruss_aus_kiel_svendura.gif

PS: Please excuse any spelling mistakes, clumsy words or poor grammar.
English is not my native language and the only one to blame is Mrs
Hardenberg, who was my english teacher at school :-)
____________________
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chris-red · Have you considered a TDM? Joined: 21 Sep 2005 Karma :

Isn't that the clutch switch?
____________________
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jimspeed · World Chat Champion Joined: 05 Mar 2010 Karma :

Thanks for that very interesting Thumbs Up

I would think that connector is maybe there to easily change the fuel map for poor quality fuel etc.
OH and you're English is better than most on here (including mine)
Wink

____________________
Hyosung cruise 125(passed test on, sold) Kawasaki el 252 (better than expected but sold on) Kawasaki GPZ500S first "big"bike.(sold) ZZR600 E5..Z750 2007,ER5, currently on a 2008 Enfield bullet electra x and loving it..
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Svendura · Derestricted Danger Joined: 04 Jan 2012 Karma :

@Chris-red: Yes, exactely. I just missed the word. Thank you :-)

@Jimspeed: Possibly, but then I don't understand, why there's no hint from Kawasaki. It'd be a great feature.
(thanks for the kindness, I'll pass it on to Mrs Hardenberg :-)
____________________
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chris-red · Have you considered a TDM? Joined: 21 Sep 2005 Karma :

Rogerborg · nimbA Joined: 26 Oct 2010 Karma :

Walloper · Super Spammer Joined: 24 Feb 2005 Karma :

Is the clutch Switch OK?
If that switch has a defect it could be cutting the engine ignition.

I thought the Interlock only disconnects power to the ignition to prevent start-up when in gear and clutch lever released.
If the bike is in gear the engine will not start until the clutch lever is pulled to disengage the clutch.

A bad switch could limit RPM if it makes-breaks at higher RPM due to engine vibration etc.
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Irn-Bru · World Chat Champion Joined: 13 Aug 2009 Karma :

I remember on my old Yamaha DTR125 you had to earth a wire somewhere near the headlight. The result of that was 85mph top end, up from 65 and much better acceleration. That said, the DTR is a carb'd 2-smoker but similar solution except they limited the power valve from opening - which resulting in ruining the little torque the poor engine had. If you changed gears really early a disability scooter could easily over take you.
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KTM 990 SMT & Suzuki DR-Z 400 SM

Svendura · Derestricted Danger Joined: 04 Jan 2012 Karma :

@Rogerborg: nice switch. I'd like to install it on my bike!

@Walloper: There is a second ignition curve that can be activated by bridging the clutch switch. I know of several KLX owners who already tuned their bikes this way. It works. No defective switch involved.
But you are right: Now it is possible to start the engine while in gear. But why should anybody do such a stupid thing...? :-)
____________________
www.svendura.de

Walloper · Super Spammer Joined: 24 Feb 2005 Karma :

Svendura · Derestricted Danger Joined: 04 Jan 2012 Karma :

chris-red · Have you considered a TDM? Joined: 21 Sep 2005 Karma :

Walloper · Super Spammer Joined: 24 Feb 2005 Karma :

Tango675 · Crazy Courier Joined: 24 Jul 2007 Karma :

Ok.

I think I know how this works.

The KLX250 is limited in 5 and 6th to about 7,000 rpm. This i can guess is to stop you going to quick. The redline is at 10,500 rpm and the bike does feel more spritely in lower gears.

I would guess that this fools the ECU into thinking that the clutch is engaged, removing the rev limiter and allowing the engine to reach its peak power.

I have seen other mods that do simalar things, basicly fool the ECU into thinking the bike is not in 5 or 6th.
With most solutions the ECU notices that the speedo (speed sensor) shows that the bike is going to fast and brings on the Fuel Injection light.
NB: The ECU uses a combination of Revs and speed to calculate the gear the bike is in.

The best solution I have heard is a replacement ECU that does not have the limiter built in and can accept cusom maps (for exausts, airbox mods etc) though the maps that it comes supplied with are for hotter countries and can causes starting problems in the colder UK climate.
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The Shaggy D.A. · Super Spammer Joined: 12 Sep 2008 Karma :

tahrey · World Chat Champion Joined: 07 Jul 2010 Karma :

Or a switch you can get from maplin for 50p (plus some sticky dots to hold it in place) and flick on/off as you go into 5th/4th gear?

Tango675 · Crazy Courier Joined: 24 Jul 2007 Karma :

lllN30lll · World Chat Champion Joined: 12 Jun 2005 Karma :

honda15i · L Plate Warrior Joined: 31 Mar 2015 Karma :

On ebay I found this german tuning:
https://www.ebay.co.uk/itm/Leistung-Tuning-Kawasaki-KLX250-KLX-neu-/180907884064?

Has anybody tried that?

I'm wondering if it worth to try i.e. will it add more HP after enabling second curve (clutch) and bypassing O0 sensor.
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Regards,
Arthur