Spark Plug Wires
 

I have an '87 Carrera that won't start, and in checking out the plug wires (original Beru's), I find the wire from distributor to coil is showing no resistance. Does this mean the wire is bad, and if so, would I be better off getting new Beru's, or some other brand. Also, what is the diameter of the stock wire for the '87? I've heard the Magnecor's come in larger diameter, so want to know what will fit. Thanks,

Don Ivey
Raleigh, NC

There are different diameters of Magnecor wires. If you get the fatter ones, you can easily drill out your plug wire holders to fit the bigger wires. If you do find that the wires are bad, the Magnecors are a nice replacement at a good price relative to the Berus.
The individual plug wires have resistors in the spark plug connector. I don't believe there should be resistance in the coil wire.
If you are not getting any spark at all, I would look closer at the rest of the ignition/ fuel injection before you change plug wires.
Most of the time, a failure to start is something fairly simple like a bad DME relay or reference sender.
Edit: looking at your previous posts, I see that these have already been suggested.

Thanks Graham, and yes, I've ordered sensors and extra DME, but in in checking the wires I became curious about the coil wire. The Beru's are original and I assumed they probably needed replacing after twenty years, but maybe not. I'll replace the reference sensor and see what happens. Thanks,

Don Ivey
'87 Carrera
'83 Moto Guzzi