KLX250s WFI model - No spark
 

Hello guys, I have my bike stopped for 3 months without knowing what to do more. I am desperate, really.
I have a KLX250 s EFI model, from 2010. (Europe version). My bike doesn't have O2 sensor and side stand sensor since I got it. Never had problems.

Chronology of events:

1. Bike lost compression, and later I found it was due to piston rings getting stucked in piston grooves. Because of this I runned out of battery two times while trying to start it until I found what was the problem.
2. After repair, the bike started to not start when hot. I never noticed any fails when running, but if I stopped the engine, I would need to wait a few minutes until I was able to start it again. This only happened sometimes, but after a while it started to happen all the time. Right now it doesn't even start.
3. I've no spark, tested with 2 sparkplugs. Changed the spark plug conector and no spark aswell.
4. Tested the coil, seems ok, but I'm not sure because my multimeter has a reading error and I'm not sure if is inside specification or not. Ignition winding is 5.9k ohms and should be between 5k and 7k, so this seems ok, but the secondary winding should be between 0,17 and 0,23ohm, and it says 0,6/0,7ohm. (When I touch the two ends of the multimeter the display shows 0,4/0,5, and it should be 0, so I think the coil might be good)

Now:
On turning on the ignition I can hear all the usual relay clicks, but not the little whine of the fuel pump priming. On starting, bike turns over sharply but won't fire. No spark at plug. Tested the coil off the bike, no probs.


Any ideas?

*EDIT: should've mentioned, with ignition on there are no warning lights, but when turning the engine over on the starter the FI light flashes on/off.

The no start when hot does sound like a failing coil, I have seen that before.
Not sure if the EFI version had a separate CDI but on a carbed bike I'd suggest switching to a known good CDI to troubleshoot.
AS it's EFI it could well be the crank sensor/pulse generator.

As I said in my post, at first I tough it was the ignition coil but then I checked my multimeter and when I touch both needles it should say 0.00 and shows 0,4/0,5.

The measure I got from the second winding was 0,6 (and should be 0,17/0,23) but this may well be because of the reading error so I don't know.

I will try to check the crank sensor and cdi

Your coil measurements with dmm sound good to me. When touching the probes together you read the resistance of the probes and test leads. When you take the coil readings and subtract that your are in the ballpark.
The symptoms may fit a bad pulse sensor or connection issue. The EFI computer won't know it is not getting pulses until you start turning the engine over so that is when it would show an error or failure. If the EFI doesn't know where the piston is it won't fire the plug.
Not sure about your not hearing the fuel pump running. There may be something else suspect to look into.
Good Luck.

I when I turn ignition on I already know if the bike will turn on or not just because of the sound of the pump.
Do you know any failure that makes the ECU turn off the pump?

low battery

Why do you say that? I checked with my multimeter and is always above13v. When I eventually discharge the battery (because of trying to start it with no success) I promptly recharge it.

I checked my battery, and when I push the start button, the voltage drops to 10/11v, but then stabilizes in 11,5 +/-. Is it good, or the battery could be dead?

11.5 volts while cranking the starter should be good.
I don't have info on your model so it is hard to be specific. A bank angle sensor (vehicle down sensor) would prevent the fuel pump from running at all. You could have wiring or relay failures cause that also. The EFI can stop it.
You may want to do some electrical troubleshooting to get started. Hopefully you have a schematic of your model.

I've tested the vehicle down sensor and it is good. The question is, if there is something wrong to the point the pump doesn't do the full initial cycle, shouldn't ECU display some error?

This is a video I made with the problem, at the time I could start the bike when cold, but after turning it off she never started again.

https://www.kawasakiforums.com/forum...tarting-41436/
try giving this a read and see if it helps

you may have a bad wire to one of the sensors, maybe look up a wire diagram and check the wires to them.

ps when cranking your battery sounds a little on the weak side( low cranking amps)