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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: Jim Hall on September 22, 2024, 09:45:59 AM
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Hi My name is Jim I am new to the forum.
I am the owner of a 1990 K75S which has been causing me some head scratching.
I had the battery out for charging when I replaced the battery on fitting the positive terminal the bike attempted to start ignition was off kill switch was at kill and the ECU was off.
I fitted the ECU and tried again the bike started without ignition on and kill switch still at kill I'm at a loss any advice welcome
Jim
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It sounds like your start relay has welded contacts. Try opening the relay box and giving the relay a whack.
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When you look down at the relay box, the starter relay is at the right side rear corner.
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pretty common issue, if the starter is run with the battery low for some reason the relay contacts tend to weld themselves shut. The starter will run until the battery is disconnected.
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pretty common issue, if the starter is run with the battery low for some reason the relay contacts tend to weld themselves shut. The starter will run until the battery is disconnected.
The starter will run until the battery is disconnected; or rather: dis-charged... as in DEAD ! 4265249878
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Good Evening Folks
Currently 22:00hrs here
I have just had the opportunity to read your replies to my K75S starting problem
The consensus is the starter relay and I have no doubt your experience has identified this is the problem
I will be on to this tomorrow
may I ask if I manage to tap this back into life and normal operation will it be OK, or should I replace with new
Regards Jim
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You had the battery off for charging. You install it and this happens. That tells me either your battery is unable to hold much of a charge, its connections to the starter are faulty, or the relay has just plain given up the ghost for some reason. A relay that has done this once is apt to do it again and the same condition could happen with a new one if the reason behind the problem isn't remedied. Charge up the battery again then have it load tested at an auto parts store or do it yourself if you have a suitable multimeter. If the battery and its connections are in good condition, you could clean the relay's contacts and try using it more, or get a replacement.
https://www.youtube.com/watch?v=tsJUuLu1cw0 (https://www.youtube.com/watch?v=tsJUuLu1cw0)
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The current draw of the starter is inversely proportional to rpm, so with lower voltage it draws even higher current. This tends to weld the relay contacts. Often can be freed with tapping it (somewhat hard). With good battery it will probably work fine after. I had this happen quite a number of times, gone thru batteries like candy, still running the ORIGINAL relay, 32 years old. :lets-eat:
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oops, I didn't disagree, just noticed that button and wondered what it did :johnny :laughing1:
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Hello Folks
I have charged the battery up
I have located the starter relay checked its stuck tapped firmly removed ( Contributors had it right first time)
I checked again with my battery and a couple of wires and the relay is now doing its thing so appears to be working reinstalled
Reinstalled battery and ECU
kill switch to run ignition on and it fired into life test run and all seems good
I was wondering about the battery and any potential damage so good to see the post Ref testing the battery load test with multi meter posted by Laitch
I have given consideration to replacing the starter relay and better maintenance schedule on the battery
My attention is also drawn to a slight leak below the front brake master cylinder so have to establish the cause
Your thoughts very much appreciated
Regards Jim