Re: 1970 85 hp V4

[frankr]

I believe that is a rectifier, not a rectifier/regulator. But it should be fine and that was a good price.

My water pump saga goes like this: Back along that period of time, we started getting burned up motors, one right after the other. I’m talking about nearly new motors here, generally less than two years old. The impeller hub would separate from the rubber and looked like they had never been bonded at all. This usually happened at high speed, and the instant pump failure would cook and seize the powerhead before the driver even noticed anything. So quickly, if fact, that the warning horn didn’t even have time to heat up and sound off. Then the boat sits there dead in the water and smoke coming out as the paint and wires burned off. I will say this: It was a good test for Evinrude 50:1 oil. If the guy happened to be using that,
the pistons often survived. Any other oil and it was goodby pistons and re-bore time. We had so many failures that I kept a complete stock of pistons on hand.

OK, now you probably are asking "Why?". So did we. We were in contact with Evinrude several times, and they also asked "Why?" Nobody had an answer. One factor, not to be ignored, was these were salt water motors. But they were supposed to run in salt water weren’t they?

This went on for way too long, and finally Evinrude told us they thought it was caused by electrolysis. I’m thinking "yeah, right". But an examination of impellers removed before they separated completely showed that they started to separate at both ends of the hub and progressed inward. So electrolysis might have been the culprit, attacking where the rubber meets the road, so to speak.

Anyhoo, soon after that, they got rid of the aluminum housings and went to plastic/stainless. And lo and behold, the impellers seemed to hold up better. Unfortunately, I don’t have the final answer because I left the outboard shop in 1978. And surprisingly, today nobody else seems to even be aware of the problem. Maybe it was dissimilar metals in salt water = electrolysis. (????)

But I replaced those aluminum pump housings whenever I got ahold of one.

Your mileage may differ.