Evinrude 6 hp water pump

[theodore]

I’m building (4) 6 hp engines 1977 to 1979. Some have the traditional style pump, and some have the new style plastic housing/stainless liner pump. The impellers seem puny. I was thinking of making them all traditional style/ large impeller. Anyone have a preference?

[frankr]

I like the new plastic housings with stainless liners. And they do pump plenty of water. Hey, Merc used little impellers forever, and they cooled ok.

[Mumbles]

The 763758 water pump first appeared on the ’79 six horse motors and is the dealer replacement for the older 391391 pumps. If I need a kit, that’s all I will use now as they have proven themselves on my old motors.

On the old boards there was some chatter about the small impellers taking a set after sitting for a long time so I took a ’58 CD down from the rafters which had been up there for about four years. It has the newer style pump in it and when I started the motor in the barrel, it pumped like a fire truck. I’m convinced they are OK.

[grover]

I’ve found that the older style takes more of a set than the new ones. And, as Mumbles says, the new ones pump water like crazy!

[Goman]

Is that something that would work on a ’71 Johnson 6 hp as well? I’ve had it awhile but never been into it.

Thanks
Glen

[benchrascal]

The older housings are proving harder and harder to get so eventually the newer style will be all you can get.My only beef about the newer style is they don’t have the "toothed" boss on the hub the way the older ones do .I have never had a problem with the boss delaminating on the old ones and I’ve already had several of the new ones let go.

[Mumbles]

quote Goman:

Is that something that would work on a ’71 Johnson 6 hp as well? I’ve had it awhile but never been into it.

Thanks
Glen

Yeah, they’ll fit the 5.5 and 6 horse motors from ’54 right up to ’79. 😀

[frankr]

quote benchrascal:

The older housings are proving harder and harder to get so eventually the newer style will be all you can get.My only beef about the newer style is they don’t have the “toothed” boss on the hub the way the older ones do .I have never had a problem with the boss delaminating on the old ones and I’ve already had several of the new ones let go.

Yeah, but that is a whole different topic. In fact, I had a "discussion" with a factory engineer about that about 50 years ago when OMC stopped making the toothed hubs. They haven’t ben toothed for that long, new style or old style.

[benchrascal]

The batch I bought from Sierra last year (for the old housing) all had the toothed boss .Don’t know if those were old stock ,new stock or chicken stock .At this point in my outboard hobby my wallet rules so I’ll go with what i can get a buy on.

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