1 Starter Issue - K100 waiting to be ridden but won't co-operate. Thu Jun 14, 2018 5:59 pm
elementalfire
active member
This story is slightly long winded so please bear with me.
I have been enjoying my 1985 BMW K100 for the last three years and near the end of last season the bike just wouldn't start anymore. After a glorious 1800 km trip through northern Ontario and down the Bruce Peninsula I stopped for gas 80 km from home and my bike would not start. I couldn't bump start it, I could not get it to turn over so, I managed to rent a truck and bring it home to the garage where it sat and waited.
I called my closest BMW dealership 100 km west of here and they had no idea what it could be as they had never worked on a K100. So I started with the cheapest component in the starting system which was the starter relay. It took two months to get it from Germany and it was an aftermarket component, due to the lack of availability of OEM parts for this model and year. So I had to wait till the spring to start working on it again. I installed the new relay and reconnected the battery then due to my absolute brilliance I wired the battery backwards and fried the positive side of the wiring. I then ordered a replacement wiring harness as once again it is impossible to get anything for the K100 so that took several weeks. I then spliced the wiring back together and alas once the battery is connected the battery light and clock turn on but will not start or even get a clicking sound from the starter but the fuel pump does turn on occasionally. The starter appears to work as a jump start from the battery positive side to the starter wire connection gets it to turn but no kick.
The battery is fully charged, I have checked and rechecked the harness and all is connected solidly but the battery light turns on as soon as the battery is hooked up, I have installed the old starter relay and the new starter relay with the same results repeatedly. I have taken the starter switch apart and cleaned it thoroughly and the same results once again. All the fuses are in working order so, now I am at a loss as to what to try next and I'm getting sick of seeing other people enjoy their bikes while I sit in a shed cursing at my bike.
What should I try next?
Thank You,
elementalfire
I have been enjoying my 1985 BMW K100 for the last three years and near the end of last season the bike just wouldn't start anymore. After a glorious 1800 km trip through northern Ontario and down the Bruce Peninsula I stopped for gas 80 km from home and my bike would not start. I couldn't bump start it, I could not get it to turn over so, I managed to rent a truck and bring it home to the garage where it sat and waited.
I called my closest BMW dealership 100 km west of here and they had no idea what it could be as they had never worked on a K100. So I started with the cheapest component in the starting system which was the starter relay. It took two months to get it from Germany and it was an aftermarket component, due to the lack of availability of OEM parts for this model and year. So I had to wait till the spring to start working on it again. I installed the new relay and reconnected the battery then due to my absolute brilliance I wired the battery backwards and fried the positive side of the wiring. I then ordered a replacement wiring harness as once again it is impossible to get anything for the K100 so that took several weeks. I then spliced the wiring back together and alas once the battery is connected the battery light and clock turn on but will not start or even get a clicking sound from the starter but the fuel pump does turn on occasionally. The starter appears to work as a jump start from the battery positive side to the starter wire connection gets it to turn but no kick.
The battery is fully charged, I have checked and rechecked the harness and all is connected solidly but the battery light turns on as soon as the battery is hooked up, I have installed the old starter relay and the new starter relay with the same results repeatedly. I have taken the starter switch apart and cleaned it thoroughly and the same results once again. All the fuses are in working order so, now I am at a loss as to what to try next and I'm getting sick of seeing other people enjoy their bikes while I sit in a shed cursing at my bike.
What should I try next?
Thank You,
elementalfire