Re: 71 100hp johnson ignition problem
Since you know about the neon testers, I assume you have a service manual, right?
OK the earlier suggestion was alright, sort of. Here is what you should be doing:
1. First thing first. Do it in this order. With a voltmeter, verify you have battery voltage at the purple wire on the terminal strip...the one going to the amplifier. With the key on. If you do, go to step 2.
2. Turn the key back off, then unbolt and disconnect the coil, then unscrew the whole thing from the distributor cap. Then remount the coil and reconnect to the amplifier. Rig up a spark gap from the end of the coil spark wire to ground.
3. Unplug the black and white wire leading from the amplifier to the timer base. Turn the key back on, and lightly brush the wire across a bare metal grounded part. You should get a flurry of sparks across the spark gap. If you do, you know the amplifier and coil and associated wireing is OK. If you don't get sparks, it is the amplifier or coil.
4. If that all checks out, it is time to pull the flywheel and check the points and distributor.