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Author Topic: K75 Electric disaster  (Read 6224 times)

Offline davewooley

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K75 Electric disaster
« on: June 03, 2018, 06:50:22 PM »
Took my K75 out tonight, after 500 metres riding , noticed that the headlamp was out, pulled over, noticed that the starter motor was going (motor still running), killed the main electrics, motorcycle still running. stalled the bike and the thing was still trying to take off even without the key in the ignition.
current situation, headlamp flickers when I knock the bike, otherwise electronics normal, however bike will not start.
Any ideas or help is appreciated.
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Offline johnny

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Re: K75 Electric disaster
« Reply #1 on: June 03, 2018, 07:24:58 PM »
greetings...

sounds like you need to free the starter relay contacts... then sounds like needs a new battery or a proper charge on existing battery... then sounds like you need to start it up and check the scrotator output to make sure its charging the battery... and backspin starter maintenance of course...

sounds like you need to use the search box here... its all right here...



j o



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Offline Laitch

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Re: K75 Electric disaster
« Reply #2 on: June 03, 2018, 08:00:53 PM »
Quote from: johnny on June 03, 2018, 07:24:58 PM
sounds like you need to free the starter relay contacts... then sounds like needs a new battery or a proper charge on existing battery... then sounds like you need to start it up and check the scrotator output to make sure its charging the battery... and backspin starter maintenance of course...
The starter relay is in the relay box under the tank. Scroll down in this document to see an approximate layout.
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Offline Chaos

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Re: K75 Electric disaster
« Reply #3 on: June 03, 2018, 08:17:53 PM »
+3 starter relay stuck. They all do that.  I added a battery disconnect just in case.
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Offline Rcgreaves

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Re: K75 Electric disaster
« Reply #4 on: June 03, 2018, 09:52:52 PM »
This sounds eerily like my experiece last year 1987 k75s- where the headlight flickered etc ..were traced to worn starter motor brushes and a resulting poor ground to the rest of the electrical system. 

Sent from my LGL58VL using Tapatalk

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Offline Martin

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Re: K75 Electric disaster
« Reply #5 on: June 03, 2018, 10:04:11 PM »
First time it happened to me the battery overheated and blew the side of the battery out. It happens with a low battery charge. I fitted a battery isolator switch into the earth lead as a precaution. It can also be used to isolate the battery when working on the electrics. If you remove the key it also works as a security device. See  here http://www.motobrick.com/index.php/topic,8995.msg70926.html#msg70926
Regards Martin.

* Narva Battery Isolator 5.jpg_thumb.png (579.65 kB . 688x516 - viewed 462 times)
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Offline daveson

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Re: K75 Electric disaster
« Reply #6 on: June 04, 2018, 06:58:28 AM »
This is a long shot but quick, drop the starter relay from two foot onto a concrete slab. It could free the contacts. It worked for me.
I dropped mine by accident, my first thought was i just broke my relay, my second thought was maybe i fixed it.
I put it back in and it has been working normally since.
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Offline Laitch

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Re: K75 Electric disaster
« Reply #7 on: June 04, 2018, 07:52:47 AM »
Quote from: daveson on June 04, 2018, 06:58:28 AM
This is a long shot but quick, drop the starter relay from two foot onto a concrete slab. It could free the contacts. It worked for me.

:giggles

Even quicker is rapping on it with the butt of a KA-BAR without removing it from the box.
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Offline bizzaro

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Re: K75 Electric disaster
« Reply #8 on: June 04, 2018, 10:08:07 PM »
Quote from: Chaos on June 03, 2018, 08:17:53 PM
+3 starter relay stuck. They all do that.  I added a battery disconnect just in case.


So I can assume that the kill switch will not cut power to the starter and starter relay? How bouts if ya pop up the tank and disconnect the ignition connection. That should work in an emergency? And maybe quicker than fiddling with a wrench trying to disconnect the battery.  Just want to be prepared. Ya never know, :dunno2:
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Offline Martin

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Re: K75 Electric disaster
« Reply #9 on: June 05, 2018, 12:37:05 AM »
The only way to stop it is to rap on the relay, or disconnect one of the battery leads, preferably the earth lead. The lead as you are disconnecting it can get extremely hot, hot enough to burn fingers. The best option for me was to splice in an isolator switch into the original earth lead. The switch is pretty much hidden from view, and could be made totally unseen by painting the red key flat black.
Regards Martin.
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Offline Mongrel

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Re: K75 Electric disaster
« Reply #10 on: June 05, 2018, 03:54:06 AM »
Quote from: daveson on June 04, 2018, 06:58:28 AM
This is a long shot but quick, drop the starter relay from two foot onto a concrete slab. It could free the contacts. It worked for me.
I dropped mine by accident, my first thought was i just broke my relay, my second thought was maybe i fixed it.
I put it back in and it has been working normally since.
This is the best kind of repair.  :clap:
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Offline davewooley

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Re: K75 Electric disaster
« Reply #11 on: August 12, 2018, 12:20:35 PM »
Wow, what a great community! Cheers for the help.
Removed the starter relay, tested on a battery, seemed fine, when in doubt, replace anyway...
problem persisted, changed the starter brushes and finally discovered a badly earthed rear brake light playing other tricks.
electronics fixed... On to the next problem.
Thanks guys.
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  • Italy
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