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Author Topic: No start, please help  (Read 16344 times)

Offline EdwarddRichtofen

  • Motobrick Curious
  • Posts: 21
No start, please help
« on: April 28, 2025, 08:42:30 PM »
Hello, I am unable to start my 1991 BMW K 75S. I have replaced the battery, starter relay, and the starter. I am able to bump start it, and ride it around no problem, however, when I press the starter button, I get nothing. No click from the relay, and the headlight does not dim. What could be my issue?
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  • In my living room
  • 1991 BMW K75S, 1996 BMW R1100R, 2001 Suzuki SV650s (RIP)

Offline The Mighty Gryphon

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Re: No start, please help
« Reply #1 on: April 28, 2025, 09:31:46 PM »
The starter is interlocked so the transmission has to be in Neutral or the clutch lever pulled in.  Sometimes there is a problem in the instrument cluster with the neutral interlock.  In that case pulling in the clutch lever will allow the starter to work.

Have you tried starting with the clutch lever pulled in?  If that works, there is a problem with the neutral.  Is the bike in Neutral? Is the green neutral indicator light on when you try to start? 
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  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline EdwarddRichtofen

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Re: No start, please help
« Reply #2 on: April 28, 2025, 09:32:36 PM »
It does not work with the clutch lever pulled in… I’ll have to check about the neutral indicator light
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  • In my living room
  • 1991 BMW K75S, 1996 BMW R1100R, 2001 Suzuki SV650s (RIP)

Offline Chaos

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  • Mars needs women!
Re: No start, please help
« Reply #3 on: April 28, 2025, 11:11:50 PM »
Mine did that when the button switch on the clutch handle went out.  But it would start in neutral.  Those are the same switches used on the brakes and fail pretty regularly. About $70 at max's btw
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  • sw ohio
1987 K75S    VIN 0231
Original owner, Original litter
200,000 miles (plus or minus) and 5 paint jobs
sold 6/23
2023 Ural 2WD sidecar (BMW's bastard step child)

Offline frankenduck

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Re: No start, please help
« Reply #4 on: April 29, 2025, 12:31:29 AM »
The BLK/YEL wire to the starter relay is what engages the starter relay. It should be 12V when the start button is pressed.

The are two BLK/GRN wires that feed power to the start button. One has 12V from the cluster when the bike is in neutral and the other has 12V when the clutch lever is pulled in.
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Offline EdwarddRichtofen

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  • Posts: 21
Re: No start, please help
« Reply #5 on: April 29, 2025, 02:59:01 PM »
Bike is in neutral, no neutral light. Still does not start with clutch, pulled in or a neutral.
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  • In my living room
  • 1991 BMW K75S, 1996 BMW R1100R, 2001 Suzuki SV650s (RIP)

Offline The Mighty Gryphon

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Re: No start, please help
« Reply #6 on: April 29, 2025, 03:56:05 PM »
Do you get 12V on the Black/Yellow wire at the connector on the starter relay when you press the start button?  From there you would have to back up to the Right hand grip combination switch to check the start button.
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  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline Laitch

  • Faster than a speeding pullet
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Re: No start, please help
« Reply #7 on: April 29, 2025, 04:10:15 PM »
First, I'd remove the starter button panel from the switch block and see if the starter button bridge was contacting the power wire terminals when the button is pressed because it's a one-screw-and-eyeballs procedure.
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  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline Harrowbmw

  • Curious
  • Posts: 2
Re: No start, please help
« Reply #8 on: June 04, 2025, 05:57:55 AM »
Greetings, have you upset ANY of the earths beneath your fuel tank....the ones that attach to the main frame spine of your bike?  Just asking...
Is your instrument pod plugged in fully and correctly?
Have you attempted to carefully and fully reseat your EFI control module? (the one beneath the seat)
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  • Brighton, South Australia
  • 1983 K100 1999 K1200LT
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