Hello everyone. I am looking for some help and advice.

My 85 k100 suddenly stopped starting, no Crank, nothing happens when I press the starter button. The battery is fairly new, so I think the battery is fine. I jumped the starter with cables, the bike turned over and ran for a few seconds. 
What could be the problem ? 

Clutch switch?
Neutral switch?
Starter relay?
Or pinched handlebar wiring?

I would love to learn how to troubleshoot.
Thank you for your time.

Sean

On the portal tab go to K100 forum tech page then to Miscellaneous then engine not running Fault finding. Its a PDF document so you can print it out and take it to the bike.

Is your bike a cafe racer or are we dealing with factory wiring?

Have you cleaned all the ground connections, both under the tank and on the side of the transmission?  Are the battery terminal connections nice and clean and tight?

How many miles on the bike?  Has the starter motor ever been cleaned?  A dirty starter or worn brushes will cause cranking issues.

Can you hear the start relay click when you push the start button? 


What do the lights in the instrument cluster do when you push the start button?  It's possible your ignition switch is dirty and needs to be cleaned.

Ohhimark95 wrote:I jumped the starter with cables . . .

What does that mean exactly?

Point-Seven-five wrote:Is your bike a cafe racer or are we dealing with factory wiring?

Have you cleaned all the ground connections, both under the tank and on the side of the transmission?  Are the battery terminal connections nice and clean and tight?

How many miles on the bike?  Has the starter motor ever been cleaned?  A dirty starter or worn brushes will cause cranking issues.

Can you hear the start relay click when you push the start button? 


What do the lights in the instrument cluster do when you push the start button?  It's possible your ignition switch is dirty and needs to be cleaned.

Hello, thank you for replying. This k100 has 45,000 miles on the clock, it also has stock wiring.

I just realized all of the "checking" lights on the dash are not turning on when I switch on the ignition

Is it possible if the kill switch is bad ?

Laitch wrote:

Ohhimark95 wrote:I jumped the starter with cables . . .

What does that mean exactly?

I connected a 12v battery to the starter with cables. The starter turns over.

Ohhimark95 wrote:

Point-Seven-five wrote:Is your bike a cafe racer or are we dealing with factory wiring?

Have you cleaned all the ground connections, both under the tank and on the side of the transmission?  Are the battery terminal connections nice and clean and tight?

How many miles on the bike?  Has the starter motor ever been cleaned?  A dirty starter or worn brushes will cause cranking issues.

Can you hear the start relay click when you push the start button? 


What do the lights in the instrument cluster do when you push the start button?  It's possible your ignition switch is dirty and needs to be cleaned.

Hello, thank you for replying. This k100 has 45,000 miles on the clock, it also has stock wiring.

I just realized all of the "checking" lights on the dash are not turning on when I switch on the ignition

Is it possible if the kill switch is bad ?

I have an 83 RS and if the kill switch is off then the dash lights are also off. So if the kill switch is faulty then all is dead!!! The kill switch is known to go faulty so maybe a replacement right hand switch gear is in order. Not expensive. Try www.kpartsholland.com www.motorworks.co.uk

I would suggest making sure the battery is fully charged.  You didn't mention how old it is.  It may be a good idea to take it to a local auto parts store to have it load tested.  This will tell you if it is capable of putting out enough current(amps) to run the starter motor.

If you haven't already, check the ground connections on the frame under the tank and on the side of the transmission above the shifter.  These need to be clean.

While you have the tank off to check the grounds, take the cover off of the relay box and try to start the engine.  Listen for the start relay to click.  There will be two heavy wires connected to the start relay.  One goes to the battery and will have 12v on it.  The other wire gets 12v when you push the start button.  Check for that voltage and get back to us.

Another quick check, turn the ignition switch to on. You should hear a faint click from the relay box, that's the load shed relay. If it doesn't click, look at the ignition switch. If it clicks, it's getting power from the ignition switch, then look at fuse one and the kill switch.

daveyson wrote:Another quick check, turn the ignition switch to on. You should hear a faint click from the relay box, that's the load shed relay. If it doesn't click, look at the ignition switch. If it clicks, it's getting power from the ignition switch, then look at fuse one and the kill switch.

Hello thank you for the amazing tips, I just did a quick test, the load shed relay does click, and the fuse 1 was blown. I put in a new fuse, the dash works busy now, but still can't start.

What do you suggest me to do next?

Thank you.

Keep an eye out on fuse one, if it blows again that should probably be your new priority. Have you done many miles and then it suddenly stopped while riding, or worked well but now won't start? Have you done some recent work that might have caused the fuse to blow. Or an accessory switched on causing a short. 

Which lights come on with ignition, and starter button. 

Does it now crank but won't start?

If it doesn't crank, I'd use a computer safe test light to check for power at the starter relay, power at pin 30 even with ignition off, power at pins 86 and 87 with ignition on and starter pushed.

Ohhimark95 wrote:

daveyson wrote:Another quick check, turn the ignition switch to on. You should hear a faint click from the relay box, that's the load shed relay. If it doesn't click, look at the ignition switch. If it clicks, it's getting power from the ignition switch, then look at fuse one and the kill switch.

Hello thank you for the amazing tips, I just did a quick test, the load shed relay does click, and the fuse 1 was blown. I put in a new fuse, the dash works busy now, but still can't start.

What do you suggest me to do next?

Thank you.

try pulling in the clutch and attempt a start 

without neutral light activated it wont start , the clutch lever bypasses that function 

also check if it has a sidestand switch (later models only )

I just finished getting my 85 k100 on the road. Had the Exact problem. Replaced the fuse 1 and so far hasn't repeated itself. Been a couple months now. Not sure what caused it, just know its working now. Searched for cause with no results. Loaded up on fuses to carry on the bike just in case.

Bill

fishboy316 wrote:I just finished getting my 85 k100 on the road. Had the Exact problem. Replaced the fuse 1 and so far hasn't repeated itself. Been a couple months now. Not sure what caused it, just know its working now. Searched for cause with no results. Loaded up on fuses to carry on the bike just in case.

Bill

I had that problem one time too. Faulty fuse, not blown.

92KK 84WW Olaf wrote:

I had that problem one time too. Faulty fuse, not blown.

 I  had just purchased the thing. I got it home and it happened. Thought I had bought a POS.
Was very frustrating. Found the blown fuse replaced it and haven't had an issue since. Go figure...
In your case Olaf, did the fuse appear ok? If so that could have been a bear to troubleshoot!

Yes the fuse looked ok and thats also got lots of posts too.

Fuse looking good does not necessarily mean its good. Common issue.