1 Speedo fixed Fri Feb 01, 2013 12:26 am
Ghost who rides
Life time member
Background
When I got this '86 K75C the speedo and tacho were intermittent, a tap on the cluster would restore the tacho and sometimes the speedo. Research on BMWOUSA (this was 4 years ago) gave the solution so ripped into it and did the job and would have been sucessful except I used a product that even now am ashamed to reveal! Even to you guys!
Well it actually did improve the situation, the tacho has been good for 20k kms, great. the speedo has been working maybe 50%, typically nothing on the first part of the ride then rock steady accurate for the next, fill up with juice and back to square one. Heating up of the contacts?
Forum to the rescue.
Since then i've found Flying brick and K100 Forum and having read extensively many cases of the same problem I attacked the cluster for the second time, last January. Oh no ! Worse ! How can that be when I am a forum "Expert"? Now the needle was "I think I can, I think I can " struggling up there and sometimes making it but ohh soo tired and just as often sliding back. Damn!
I can cope with estimating my speed by the revs and haven't been booked for speeding but it's the odometer I miss, not being able to brag about the 1 thousand and something km day ride, or calculate the fuel consumpion or range.
Back to the Forum
More threads have come and gone in the last year and now i'm ready for the final fix. To tell the truth I love pulling the thing apart even tho i've only done it 3 times it's a nice clean challenge that rewards gentle handling and cleanliness, good fun.
This time I cleaned even more traces of the crap mentioned above, DeOxit of course (did that last time too) then looked very closely at the pins and sockets because Charlie and others mentioned corrosion. I noted that the female part of the socket had a side that was sprung to grip the pin, on the 4 in a row set below the speedo it was easy to push the "spring" in a bit to give them more bite but the 3 pins in a row that do the speedo this was'nt possible due to them being hidden on a circuit board with stuff in the way.
So... If I can't make the sockets tighter I decided to make the pins larger by soldering , very thinly like Charlie did, but maybe on something else? the multipin connectors on the outside showed some plating missing on 4 of the pins so they got tinned also.
DeOxit followed by the gold stuff again and slip her back together.
oOn the bike now and decided to use the test attributed to Rick G of soldering iron near the wheel sensor and hey bingo 60 and a bit ( hard to see crouched at the back wheel!) great!
On the road test
Honestly felt like a new bike, first time in 5 years with a rock steady speedo.
Thanks to all the real forum experts who made their knowledge so freely available
Part 2 tomorrow when I can get this real computer again, where i want to pose a question, and make a couple of suggestions.
see ya
Part 2 i'm back, got the computer for 5 more mins.
Question. Is there a definative, complete how to on the forum for the speedo fix? I google searched but only came up with threads that I'd already read which only give part answers or links to other threads. I was looking for two specific photos Inge's labelled multipin photo and another but only found one in the end. As it turned out I knew what to do but wondered if this common problem could be covered ( if not already, pardon) for others searching?
Being a bozo with a computer limits me ie photos and diagrams, anyone got the time and skill?
cheers GORDO
When I got this '86 K75C the speedo and tacho were intermittent, a tap on the cluster would restore the tacho and sometimes the speedo. Research on BMWOUSA (this was 4 years ago) gave the solution so ripped into it and did the job and would have been sucessful except I used a product that even now am ashamed to reveal! Even to you guys!
Well it actually did improve the situation, the tacho has been good for 20k kms, great. the speedo has been working maybe 50%, typically nothing on the first part of the ride then rock steady accurate for the next, fill up with juice and back to square one. Heating up of the contacts?
Forum to the rescue.
Since then i've found Flying brick and K100 Forum and having read extensively many cases of the same problem I attacked the cluster for the second time, last January. Oh no ! Worse ! How can that be when I am a forum "Expert"? Now the needle was "I think I can, I think I can " struggling up there and sometimes making it but ohh soo tired and just as often sliding back. Damn!
I can cope with estimating my speed by the revs and haven't been booked for speeding but it's the odometer I miss, not being able to brag about the 1 thousand and something km day ride, or calculate the fuel consumpion or range.
Back to the Forum
More threads have come and gone in the last year and now i'm ready for the final fix. To tell the truth I love pulling the thing apart even tho i've only done it 3 times it's a nice clean challenge that rewards gentle handling and cleanliness, good fun.
This time I cleaned even more traces of the crap mentioned above, DeOxit of course (did that last time too) then looked very closely at the pins and sockets because Charlie and others mentioned corrosion. I noted that the female part of the socket had a side that was sprung to grip the pin, on the 4 in a row set below the speedo it was easy to push the "spring" in a bit to give them more bite but the 3 pins in a row that do the speedo this was'nt possible due to them being hidden on a circuit board with stuff in the way.
So... If I can't make the sockets tighter I decided to make the pins larger by soldering , very thinly like Charlie did, but maybe on something else? the multipin connectors on the outside showed some plating missing on 4 of the pins so they got tinned also.
DeOxit followed by the gold stuff again and slip her back together.
oOn the bike now and decided to use the test attributed to Rick G of soldering iron near the wheel sensor and hey bingo 60 and a bit ( hard to see crouched at the back wheel!) great!
On the road test
Honestly felt like a new bike, first time in 5 years with a rock steady speedo.
Thanks to all the real forum experts who made their knowledge so freely available
Part 2 tomorrow when I can get this real computer again, where i want to pose a question, and make a couple of suggestions.
see ya
Part 2 i'm back, got the computer for 5 more mins.
Question. Is there a definative, complete how to on the forum for the speedo fix? I google searched but only came up with threads that I'd already read which only give part answers or links to other threads. I was looking for two specific photos Inge's labelled multipin photo and another but only found one in the end. As it turned out I knew what to do but wondered if this common problem could be covered ( if not already, pardon) for others searching?
Being a bozo with a computer limits me ie photos and diagrams, anyone got the time and skill?
cheers GORDO
Last edited by Ghost who rides on Fri Feb 01, 2013 12:54 am; edited 1 time in total (Reason for editing : extra paragraph)
__________________________________________________
1986 K 75 C 2nd owner 187,000kms showing .
1987 K100RT Police repainted, rough and unloved.