Re: 1972 evinrude 125hp converted?
I think F_R did answer your question, in his discussion of the role that the battery plays in your ignition system. I can see a situation where you could get spark for a minute or so and then lose it, if the battery were right on the edge of being dead. An easy way to see if this is the issue, is to just charge the battery and see if they is any improvement.
Given that your motor has had some wiring problems, however, you could also have some issues there. A badly spliced wire, some corrosion at the splice, etc, could be casuing an intermittant situation.
Its also possble that the battery connections are bad. This is a pretty common situation. The first step here, is to make sure that all of them involve good metal to metal contact with no corrosion and that they are all tight.
Its pretty hard to troubleshoot a motor by forum entries, when these sorts of possibilities exist. I really think that you either need to find a friend who has enough knowledge to go over the motor with you, or you need to find a competent mechanic, who can perform some real trouble shooting. If the rectifier looks like it is toast, that's a good place to start. I would still go through the rest of the wiring though.
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