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1977 Johnson 55 hp cooling

S

SCross

New member
Hi,
I have a 1977 Johnson 55 hp I recently purchased to get back in running condition. I replaced the impeller and thermostat (and a lot of other stuff) and it runs good, but I don't have any cooling water exiting the motor above the water line. The two slots at the rear base of the power head have nothing coming out of them while running and water hose hooked up. There is what seems to be a pee hole at the front of the lower unit where it mates to motor that starts flowing as thermostat warms up. Is that all I should see? Warm water is coming out of there and block temp fluctuates between 140 and 170. Is this normal? Just used to seeing water exiting above water line somewhere. Thanks.
 
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In the first place, you cannot test a water pump by running on muffs. The pump is not pumping when you are doing that, only allowing hose water to flow through.

In the second place, there should be at least a mist blowing out those slots at the base of the powerhead, if running in the lake where it is supposed to be.

The hole you are speaking of is a drain hole to drain the exhaust housing which fills up with water when running. The fact that it is warm indicates it probably has circulated through the powerhead, but is not a reliable test
 
Thanks, have lots of water coming out now, used a water trough because closest lake is two hours away.
 
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My motor is the same era- I don't believe they came with pee holes off the block from the factory, but it is a very common addition.

The rear ports are probably exhaust reliefs - when idling the exhaust can't make it out via the prop (when in water, not muffs). They are also part of the exhaust housing cooling system. Water will pour out of these when under normal operation.

The cooling system works really badly when on muffs :)
 
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