Hello Group,

The other day I went for a short ride an everything seemed to work as it should, after a stop over at a friends shop, I was about to leave and proceeded to start my bike; key turned to on, dash lights lit up as normal, pressed the start button and nothing...dash lights faded. Okay, that was weird so I tried again...same results...hmmm? Dead battery seemed unlikely but something was amiss, checked fuses, all good, only thing to do now was dig in a little deeper. To fully access the battery on my '86 K75C you must remove the brain, so I did to take a closer look, everything appeared in tact, I then tried to to charge the battery but it did not make a difference. I noticed an odd odor, and the battery felt hot, hmmm, not good, then I see a slight whiff of smoke, I quickly disconnected the battery. Okay, there is definitely a problem with the battery but what the hell is going on here? My friend suggested the battery had a short, I've never heard of that, but okay. I purchased another battery and connected the positive side but when I attempted to connect the negative side the starter would engage, what the hell? I was careful to make sure sure all cables previously connected to the positive side were the same, ditto for the negative terminal as well. So that's where I'm at right now. I'll be picking the bike up today to trailer it home where I have space to try and sort it out. Anyone care to opine, offer advice, or just make me look silly for overlooking something that should be obvious to even the most electrical knowledgeably challenged. I'm stumped. Thanks

Keith

This look like a stuck starter relay.
First you have to see if you don't have a short somewhere.
Diconnect the starter relay (in the electrical box under the tank).
Reconnect your battery installing an ampmeter in serie with the positive. It should indicate a load of only few milliamps (clock).
If it's OK, turn your ignition key ON. you should see a load of approximatly 5 amps. (This is your headlight, tail light, instrument cluster and computers getting power from the battery).
If you get a lot more, you may have a short or..... the contacts in the ignition switch are corroded.

Good luck

Bert

Your starter motor relay got stuck. I had the exactly the same problem. Now the first thing to do is to let the starter relay get back to where it should be. As I understood in my case, the battery went off just in time the relay was on, so the battery went off and the relay simply got stuck. And nothing helped - I put the wires to the battery, +, then put - and the starter starts working. What you should do:

1. Charge your battery well.
2. Put the battery and connect +.
3. Put everything in its place (computer, etc.)
4. Turn ignition on, with full throttle.
5. Connect the "-" and keep it for short time. There might be sparks (at least in my case there were plenty of them), but the engine turned on and the relay got back to it's position.
6. Tighten the "-" well.

I'm sure that in 100% the problem lies here. I had this problem twice....

I'm sure that in 100% the problem lies here. I had this problem
twice....

Same problem twice..shame on you. Did you not overhaul your starter motor. Ajays

Shame on me. Yeah, right, the most terrible person in the world... How dare I?

This happened twice, the first time when battery went off, the second time when I left the lights on...

Has happened to most of us but overhauling the starter motor in my case made absolutely no difference. It was as Bert suggested dirty ignition switch contacts.

And trust me I have done a lot of reading on the subject and there is more than one fault that will cause this and the worst part is it can be a bit intermittent and just when you think it is fixed it will surprise you.

Hi This is not unusual if you try and start with a failing battery. The procedure for the condition where the starter starts to turn every time you connect the battery is to disconnect the battery+ then loosen the petrol tank and prop it up securely and take off the top of the relay box. Give the starter relay a sharp rap with the handle of a screwdriver or a hammer handle and touch the battery connection to the relay. With any luck you will have jarred the relay contacts free. Reconnecting the battery should allow you to start normally and when you switch off the starter should not be turning unless you are pushing the start button that is!
At this point I believe you should take out the starter relay (after disconnecting the battery) and clean up the contacts of the relay with a diamond file or some clean high quality emery paper.buff the contacts with clean cloth and reassemble.
You should then be good to go.

If this happens on the road you can try whacking the side of the relay box closest to the starter relay to jar it free. With any luck that will work and allow you to think what you do whilst the starter is not churning round any more. Once you are in that happy place you should be able to bump start the bike and as long as you keep the revs above 1500 or so you should have plenty of volts to get you home. The only proviso is never try to drive home with the battery disconnected you will do a lot of damage to the engine management module, the ABS module (if fitted) and the alternator diodes.
Regards,
K-BIKE

As chief inspector clouseau would say, 'prob-lem solv-ed.' Thanks to everyone who chimed in.

I pulled off the gas tank to access the relay box, removed the starter relay and cleaned the contacts; with everything exposed, thought this would be a good time to clean and check all the connections that reside under the tank. With everything de-oxidized and re-connected I re-installed the tank, connected the battery...no sparks flying this time or starter trying to engage..finished fitting it back together. Key turned to on, choke moved to position 1, start button depressed...VROOOMM!, sorry not sure of a good sound description for the K75. Everything back to normal.

So, I learned some new things about my bike; it's the first time I've had the tank off, have an even stronger appreciation of this forum, and now I'm going to ride to the beach before it becomes an oil slick. Thanks everyone for the support.
Keith

Well done Keith!
Regards,
K-BIKE