Author Topic: K75S cranks, no start  (Read 3340 times)

Offline 3dachshunds

  • Motobrick Curious
  • Posts: 28
K75S cranks, no start
« on: May 15, 2025, 10:46:24 AM »
Happy Thursday!

I recently bought this beauty 1992 ABS red K75s in unaltered condition. Rear brake reservoir was dry and MC seized, and I have been working on it (I started separate thread on rear MC and thanks to everyone who responded).
I finally received new battery yesterday and tried to start the bike without success. But let me tell you little bit about the bike. I bought it from an online broker which mostly sells insurance vehicles, and charity donated vehicles as well, which this bike was. So I have no knowledge about maintenance history etc. But the machine appears meticulously maintained, all tools and user manual neatly stored. It has 14k something miles. All lights work except of break light.Original battery had 06/2017 written on on it with sharpie, so I presume the bike has not run for years.
I put about half gallon of gas. I checked spark plugs, all firing when grounded on earth, all fuses are intact (checked with multimeter). I couldn’t hear fuel pump running when cranking. There is no voltage at either green or white wires of 4 pin connector of the tank when cranking. The pump appears visually intact and its grommet does not appear deteriorated. Not sure how to proceed with diagnostics. Any help appreciated!



  • USA
  • 1992 BMW K75, 2013 Triumph Tiger 800 roadie

Offline frankenduck

  • Adrninistrator
  • ^ Quintessential Motobricker
  • Posts: 5511
Re: K75S cranks, no start
« Reply #1 on: May 15, 2025, 11:37:49 AM »
Check the connector the the fuel tank. Under right side cover w/ 4 wires:
GRN/WHT
WHT
YEL
BROWN

Detach and reseat the connector for the L-Jetronic. (Under rider portion of seat.)

Jiggle the ignition key. The ignition switch internals can get dirty.

http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/ignition2vclean/ignition2vclean.htm
Once I had a Collie pup. Dug a hole and covered him up. Now I sit there by the hour. Waiting for a Collie-flower.
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Offline 3dachshunds

  • Motobrick Curious
  • Posts: 28
Re: K75S cranks, no start
« Reply #2 on: May 17, 2025, 12:24:29 AM »
Update: Got the bike started and the engine sounds great! I came across you tube video where the presenter squirts small amount of motor oil in each cylinder of a bike that was stored for long time and would crank bot not start. He says this brings to increase compression and helps with the start. I did the same. I took several minutes of continuous cranking. Now I am back to rear brake fix, since my cheap ebay MC has arrived.
  • USA
  • 1992 BMW K75, 2013 Triumph Tiger 800 roadie

Offline natalena

  • ^ SuperNatural Motobricker
  • Posts: 742
Re: K75S cranks, no start
« Reply #3 on: May 17, 2025, 02:39:42 PM »
Update: Got the bike started and the engine sounds great!
Awesome, great to hear you got the brick purring 3dachshunds ... you're a WEINER, weiner, chicken deeeeiner.

Sorry, it was just too low hanging 😉
  • MST
  • 1987 K75s #0919, '05 Sportster 1200C, '21 ARGO 8x8, '24 KLR650
"Hard to beat a 10x beaver, 'specially if you're gonna work it."

Offline 3dachshunds

  • Motobrick Curious
  • Posts: 28
Re: K75S cranks, no start
« Reply #4 on: May 19, 2025, 01:26:58 PM »
LOL! Actually 7 dachshunds at the moment. Still looking for forever home for two sweet boys, they just turned 6 months old.
  • USA
  • 1992 BMW K75, 2013 Triumph Tiger 800 roadie

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