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K75 Weak/No Spark Wed Feb 10, 2021 4:57 pm
RetroRebuilds
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Picked up a non running 1992 K75 with a stuck starter relay. When I first got the bike it had no battery, installed a new one but right away noticed the starter was engaging as soon as I touched the terminal. I replaced the rely and it would turn over when pressing the starter button but then only once and then it wouldn't work again until I would unhook the negative terminal, after several attempts at this I noticed the gauge cluster light would all go dim when cranking as well, I unplugged the gauge cluster and then it would crank on demand every time, but still wouldn't start. Here is a list of things I done so far as I have another K75 (running) that I have been swapping parts from for testing.
- Changed Hall Sensor
- Changed Coils/wires
- Changed relays
- Changed temp sensor
- Cleaned grounds
- Check earth continuity to coils
- #1 coil has No spark 2-3 have weak spark
- If I take the 12v lead from coil #2 and put in #1 it sparks but the #1 lead isn't working
- All coils have 12v to them
- Unplugged and check connections under tank.
- This bike didn't look to have any other electrical mods or anything that have been tapped into over the years, it all looked original.
- From past experience it seems like there is a short to ground somewhere that is pulling voltage from the coils?
- Also the top fuse in the fuse box has a dimmer light then the others when testing with probe but still reads 12v.
Any suggestions on what to try next would be greatly appreciated
Thanks
- Changed Hall Sensor
- Changed Coils/wires
- Changed relays
- Changed temp sensor
- Cleaned grounds
- Check earth continuity to coils
- #1 coil has No spark 2-3 have weak spark
- If I take the 12v lead from coil #2 and put in #1 it sparks but the #1 lead isn't working
- All coils have 12v to them
- Unplugged and check connections under tank.
- This bike didn't look to have any other electrical mods or anything that have been tapped into over the years, it all looked original.
- From past experience it seems like there is a short to ground somewhere that is pulling voltage from the coils?
- Also the top fuse in the fuse box has a dimmer light then the others when testing with probe but still reads 12v.
Any suggestions on what to try next would be greatly appreciated
Thanks