Hi all,greetings from Finland!

a K75 c -87 (110K kms) began behaving oddly right after I took it out last May. Bike started immediately for a while until I switched her off. After that, no go. Starter motor turned but it sounded like something was wrong with the sprag clutch. Motor won´t start. Battery was sound, fully loaded. Decided to overhaul both starter motor and alternator. Checked also plugs and changed two gasoline hoses (tank to rail, return).  Opened all the under tank connectors ( not the handlebar switches connectors) and used Deoxit like stuff. Overhauled starter switch (thanks Don Eilenberger)but not the start button. Looked also into the relays  box, nothing loose nor corroded, no smell. Cleaned the tank inside, there was some black stuff, not plenty of it. Changed fresh gasoline.

And she started and run perfectly. Taking her to the road after 2 kms riding motor suddenly stalled just like if I had used the kill switch which I did not. All instrument  lights stayed on, and I could jump start it immediately, not even stopping first. 

Same has happened after that  two- three times. Just dying suddenly and (jump ) starting immediately.

Any idea where to look next? I think next I´ll let her run for one hour at our summer cottage to see if it´ll die or not, then try again on the road. If it happens only when riding, would that indicate loose connection?

Thanks for replying and excuse my english

Pasi Viitanen

Check and refurbish the ignition switch.

If cleaning or replacing the electrical portion of the key switch doesn't work, then check the kill switch.

i think it's just one screw on the back of the right handlebar to open the compartment with the kill switch and starter button.  Clean the kill switch contact surfaces of the slider nubs and the ring and be very careful of the tiny springs.  If that sliding contact surface gets dirty it might behave such as you have seen, an intermittent contact--the hardest thing to troubleshoot.

robmack wrote:Check and refurbish the ignition switch.

What he said.

Or replace it.

Thanks guys, I was actually beginning to check kill switch next. Never done that. Do You know any how-to´s?

Instruments and lights etc staying on could be that darn connector to the fuel injection control unit under the seat. Check it out because I have seen it on a few and even had it on my own K100RT. The plastic retainer part can crack and leave it loose.

As others have said, check the electricals. Maybe the neutral switch or sidestand cutout. ( Did any have a sidestand cutout?) Unless of course you are revving past the limiter.

Yes Woody the neutral switch must be cheked. And Olaf, EFI connector is OK, It clicks nicely and is steady. I think must refurbish the kill switch if stalling happens again.

If it happens again, before jump starting and going on--can you check to see if the headlight is still on or off, also are the Instrument Cluster lights on or off?

It may be two separate contacts in the key switch--the headlight should be on with the key ON, but the IC lights only come on when the Kill switch is in RUN.  If you have headlights but no IC lights, then the Kill switch may be the culprit...but the ignition switch is still suspect due to the separate contacts.

If my take is right the clutch switch or neutral light one or other is required for starting only. If neutral light is on then clutch switch is not needed. If you have no neutral light or are not in neutral then clutch switch is needed. But only to run the starter motor. Neither would cause a cut out.

Funny little thing too....on one of the K75s I encountered that problem we noted the low seat option seat protrusion underneath was pressing down on the FICU.