looking at a wiring diagram for efi klx the clutch switch is only part of the starter interlock circuit, has no connection common with the ECU? hard to see how it would effect a rpm limit?

also the trans only has a neutral switch, no gear position indicator, so can't see how the ECU would know what gear it was in ?

 

There is a lot of interconnection between the ecu & the sub throttle sensor & the main throttle body sensor....and many many more sensors on the efi bike.

If the clutch by-pass is done correctly the bike will not be restricted to 8000rpm in 4th, 5th & 6th gear. It will rev to 10,500rpm and then hit the rev limiter.

The other cool thing about the clutch by-pass is, if i stall the bike or it cuts out for some reason it can be immediately started in any gear without having to select neutral!

 

The clutch switch, does not tell the ECU which gear is selected, it only tells the ECU if the clutch is engaged or disengaged. The clutch switch on a standard bike is closed when the lever is pulled and open when clutch is engaged.
Shorting out the connector tells the ECU that the clutch lever is always pulled (clutch disengaged), the ECU then seems to ignore the speed sensor input and allows the full rev range at any speed.
On a standard bike the ECU takes the input from the speed sensor and IF the clutch is engaged cuts the high end power above a certain speed.
Removing the speed sensor input to the ECU also aledgedly has the same derestricting effect.

The standard bike will start in gear, but only with the clutch lever pulled. The modded bike will start in gear irrespective of the clutch - this is an easy way to check if your mod has actually shorted the switch cable: try to start the engine in gear with the clutch engaged (but make sure the sidestand is UP!!!!), if the starter turns the clutch switch is shorted.

Even after this mod the KLX250 is hardly a bionic duck

 

Thanks for that / like this I can easily check if my shortcut is applied at all!
On top I also ordered this O2 Oxygen Sensor Elimiter on Ebay. That should arrive next week.
.. then I will check the other options and let you know.
Peter

 

Ok, I had to be sure on this....so I have just gone outside to my bike & pulled out the clutch by-pass wire & with bikes side stand up WILL NOT start unless in neutral.

Put the by-pass wire back in the bike will start in any gear....clutch lever in or out position.

Ps. This is a good way to check if your clutch by-pass is working properly.

 

Welcome to the forums raulor, I don't have any thoughts on the mod you are trying to do, but glad to have you here on the site.

 

It must have been a bad connection of the wire I plugged in. I tried the suggested test - and hoppla! I could start the machine with a gear inside and it turned. Then I tried it (in darkness and at meanwhile -3 degrees ). It has improved. The 4th gear goes up to 100 at 9500rps, the 5th then to 115 at around 8000 and the 6th well - could not get it much faster around 120 but for sure it did not slow me down anymore. I am a step further. Maybe my Metzeler rough cross tyres also play a roll in the topspeed.

Does anyone of you have an idea what the difference is between a KLX and a KLX S? Mine is a French model built in 2010 and the papers say the type is LX250S Variant S Version 1A. On the Sticker it says KLX 250.

Another Thing - this CO2 Sensor Eliminator, will it do me any good? I bought for only 15 € so it is not a big investment.

I AM HAPPY anyhow. The topspeed is one thing but the smooth and easy handling is really impressive. I bought it because my wife and my son will get some driving lessons on this bike. It is perfect! Greetings from ice-cold Germany!

 

Is there a similar mod for the 06 carb model? Mine cuts out around 7000 rpm in the upper gears. I never realized it may rev higher in the lower gears???

 

wiring diagram I was looking at:

http://mototh.com/files/kawasaki/KLX...Manual_new.pdf



thoughts:
if it's not pulling rpm in higher gears it could just be it just can't pull the tall stock gearing?

speed sensor for the 17" front differs from the 21", output is in hertz. One may be able to fool the ecu with a simple circuit telling the ecu your going slower than you are. Circuit installed between the speedo and the ecu would still keep the speedo accurate.

most rev limiters are enabled/ disabled (or changed) by grounding or ungrounding one pin at the ecu. That's what I was looking for in the wiring diagrams.

an 06 klx250s carbed usa model can pull hard to redline if jetted and geared without any wiring tricks. But won't in the upper gears if it's overall gearing is tallish.

 

The eliminator is very worth while. Nothing earth shattering but for 25 bucks, improved throttle response & a slightly enriched fuel map! The 02 sensor is only on the bike to keep it lean enough to pass Euro3 emission laws.

Enjoy your not so lame klx