Dual coil wiring issues - R80G/S

[loris199]

Hi all,

i am replacing wiring harness on my 1987 R80G/S. Bike is equipped with two coils and wiring harness was a little bit messed up and partially customized so i decided to replace it with an original used in very good conditions.
At this point i want to connect the wire going to left cylinder coil and the wire coming from right cylinder coil.
Here below pictures of the wires:

yellow going to left cyl. coil

black coming from right cyl. coil

Taking a look at the electric scheme i am supposed to connect the couple of green wires on the yellow one and the black couple on the black one.
Here below the wires coming from main harness:

I temporary connected as per above but nothing, also starter relay / starter motor are dead.
Boundary conditions: battery OK, all the other electrics work, bike was running with the old harness.

Any suggestions?
thank you

 

[Gelandestrasse]

The R80G/S came stock with a dual output coil (one off, not 2) which should have a green/blue and a black connection, each twinned. Looking at the picture and understanding your text you have a non-standard set up.

Did you mean you just had a single, dual-output coil? If so, junk the yellow wire and connect the Green/Blue and the Black cables to the correct terminals on the coil.

If not, let's have a wider shot of the whole installation on the bike?

 

[Steptoe]

Has it been twin plugged ?

 

[DrFarkoff]

Has it been twin plugged ?

Looks like it

If you just want to get the bike running? The just use one coil and connect the green to one terminal and black to the other and connect one plug wire to each top plug

You can then figure out the Twin plug wiring later depending on what ignition you have

 

[Gelandestrasse]

For twin plug, 2-coil set up it would be likely that the green/blue goes to one coil, a link wire off the other terminal on that coil goes to the second coil, and the twinned black goes to the other terminal on the second coil. The coils are likely 6VDC and connected in series. They may or may not have polarity; if so the coil will be marked. If your coils are 12VDC then ignore me! Your ignition control box may also pick up on the green/blue (for its power) and the twinned black cable ( to trigger the coils).

 

[loris199]

Thank you very much for the suggestions.
A quick clarification: bike has two coils, connected in series, here a picture:

Before, yellow cable was splitted like this:

so i suppose it's just like the original harness...
I will try to fire it up as a single spark, but just a question: if coils are not connected properly, should starter motor work or not?
Cause i don't hear starter relay working...

thanks again

 

[Gelandestrasse]

Sounds like your kill-switch wiring is open circuit

 

[loris199]

Problem found...before going deeper into analysis i replaced starter relay with my old one, which i knew It was working 100%. Starter ok!
Then connected coil as per above (yellow on green/blue ones, black on blacks) and tested spark on one sparking plug.
Bike works!
Thank you very much for the support!
Now i just need to vent the garage

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