How to test a coil on plug type coil
Each coil is held in place by a single bolt; take out that little bolt. Disconnect the electrical connector to the coil, and then the coil and wire. You can test the coil with a digital ohmmeter.
There are two wires inside the connector and then a larger one that goes to the plug.
test across the two small connectors for the primary windings, and then from the little one that is marked bat or B+ to the large wire that goes to the plug for the secondary windings.
Using a digital voltmeter. The primary circuit from B+ to tach should be 0.3 - 1.0 ohms
The secondary windings (B+ to plug wire) should measure about 5.9K ohms (that is the measurement I got off of two new ones), I do not know what the acceptable range is.