Because he has Buach Platinum plugs  (single electrode)  I'll bet.
I've seen this several time....  NO explaination given...
   The best of the best can not figure it out!!!

Paul Guzyk wrote:

> I'm helping a fellow listee.  His 87 Westy had no spark, we
> determined the coil was bad so we replaced it with a good used one.
>
> A week later same problem, installed another used coil to fix problem.
>
> He's running now, but I'm concerned, is there anything that could be
> causing the coils to die prematurely?
>
> BTW, he does not leave his ignition key on without engine running
> (radio is hot all the time).
>
>