One for Nev - Ignition coil testing

[old man emu]

I have  a problem. My bike has a very simple ignition coil spark system, which operates through a contact breaker, not a distributor. When the timing cam opens the contacts, the electromagnetic field in the primary coil collapses, inducing a current in the secondary coil which creates the spark at the spark plug gap. I tested the circuit. I have input power (12V) at the primary coil. I have power at the contact points. To me that indicates that the Primary circuit is intact. When I try to start the bile (kick starter) There is no spark at the plug. 

 

My questions:

How do I test the secondary coil to see that it is intact? 

What other tests can I do, and what would be the positive result of those tests?

 

 

 

[spacesailor]

Test your H T lead, most modern ones are ' carbon ' & don't last that long !!!!

ALSO a magneto should Never have carbon H T leads . The resistance is too high .

spacesailor

[facthunter]

There is no distributor in that system The HT circuit is from 1 lead through the motor to the second lead and back to the coil  This causes a "Dead" spark on the 'unwanted" cylinder which is no problem except its a bit more inclined to catch on fire if you flood the motor and it kicks back as well.. They've been that way since about 1924 on the electric models. You don't do a secondary test to earth. It's only to the other Lead and catches a lot of auto electricians out  It's also used on many Japanese bikes. Those coils have pitch inside them and you have to heat the coil to fix new leads in it. The pitch helps to waterproof everything and also cool the coil. Only Use a wired type lead. NOT suppressant. You can just flick the points open with IGN on to do a test. IF you get a HT spark to ground the coil is Cactus. God rides a Harley.  Nev

[facthunter]

I'm not SURE the past sentence is absolutely true, but I'm inclined to think he'd like to. Nev

[facthunter]

Last sentence. Fat finger trouble. Nev