2009 KLX250s EFI stalls at traffic lights


New Member
Jan 27, 2009
I just want to know if anyone else has this problem on their 2009 KLX250s EFI models in the UK or any other country that has the EFI KLX250s :?: :?:

To put it simply, after riding the bike for anywhere between 5 minutes to over an hour then stopping at any traffic lights or junctions that means I have to come to a complete stop with the clutch is pulled full in & the bike is in first gear, the bike will tick over fine at correct idle for anywhere between 15 seconds to a minute then stalls/cuts out the engine all by itself, then will take at least 10-20 seconds of turning over to restart itself again.. :evil: :evil:

I have also found that the bike cannot do anymore than 75-76mph!!, the ECU on the bike reads the speed of the bike & will start to limit the rpm from 10,500rpm to approx 8000rpm after 50-55mph, then it limits the rpm again from 8000rpm to 7400rpm at the 62-70mph mark, making overtaking rather hair-raising to say the least when you go to past & have no acceleration left due to it being restricted by its rpm's.

I have an original 1990 Kawasaki KDX125sr 2-stroke that is far faster than a modern 250 4-stroke, What the hell is going on???..

Ive had the usual crap with Kawasaki UK saying there is no fault or recalls & my dealer says he cant do anything, I have seen that some thailand owners have had the dealers where they purchased the bike calling them to have the newest ECU fitted with a proper map on it that cures all the problems.. But in the UK we get nothing..

SO far I have now got my tickover up at 2000rpm as this seems to stop it from cutting out quite as much..

Also I found that some mods such as fitting the larger airbox snorkel from the kdx220 & fitting a custom made exhaust link pipe with the lamda sensor boss fitted & finished off with an old moto-x stubby-can from an old crf250 also helped slighty with curing the stalling/cutting out, but still didnt cure it & it still stalls/cuts out even with the tickover rpm at over 2000rpm

I know from reading on this website that owners in Thailand have had recalls from Kawasaki dealers due to the ecu problems, Is this 100% true & if so, can someone email me a copy of any paperwork to show that it has been a recall so I can hit my dealer with it to make someone here in the UK move their backsides & get me a new proper ecu!



Nov 2, 2008
Several of us had similar issues, and the Kawasaki Dealers changed out the original ECU for free. This solved my stalling problems, and de-restricting my bike I took care of the rev limitations – A quick search of the forum would lead you to the instructions for doing so.


Nov 7, 2007
Yeah, it's all true.

1- The ECUs were replaced free under warranty because of the stalling problem. Your dealer should do the same for you.

2 - The ECU restricts the RPMs in gears 3 and up, to a lethargic 7500 - 8000 RPM. Stupid, in Thailand we speculated it was to make the very strict emissions standards.

You have two options. 1 - get the ECU replaced under warranty, then apply a simple trick to de-restrict it if you're happy to solder some cables.

Or 2 - get a replacement unrestricted ECU which will solve both problems. De-restricted, the KLX250 is a different bike. Much, much more fun. If you do that then you obviously don't need to bother with the dealer.

On the other hand - I had my ECU replaced under warranty in Thailand, and the one I got back was actually de-restricted. The dealer was very surprised about that, and so was I. Just lucky, I guess, or maybe they mixed it up and gave me an unrestricted one by accident...

About the derestriction trick, it involves re-routing a cable. Somebody posted instructions here in the forum as far as I can remember. You should be able to find. The only reason it's not that easy to find online is because those who know about it often want to sell it for a few bucks...