Re: 50 johnson no spark
"Ignition box", "black box", whatever you want to call it, it is the power pack, and gets blamed for everything. But usually is not the cause, unless you wreck it with incorrect tests. It is the box with a about 8 wires going into it.
First test you should make is remove the cover from the power pack and disconnect the black wire with yellow stripe. Do you have spark now? If you do, the problem is somewhere forward from there, a bare wire, a bad key switch, etc.
If no spark with the wire disconnected, is the motor cranking fast enough? It has to be turning over at least 200 rpm or it won't have spark. 300RPM is more like it.
Moving on, things get more complicated and you need test equipment or replace-and-see. Or, use common sense. The involved components are the power pack, the stator coils and timer base, both under the flywheel, and the external spark coils.
Look at the area below the flywheel---are the coils melted, or soft, or cracked? If so, there is the problem.
Look at the spark coils. Anything obvious wrong? You probably don't have two bad coils at the same time, but it is possible, I suppose.
Now you are getting down to where you need test equipment---a DVA meter, and learn how to use it. Another subject. BTW, the factory service manual tells how to troubleshoot using a neon tester. Both the method and neon tester are obsolete.
