1963 18hp Evinrude water pump

[ward cleaver]

Start up 1963 18hp Evinrude after over wintering. Not moving water.
Dropped lower unit. Attached drill with LU in bucket of water. Moves water.
Re-assemble. Start it up. Doesn't move water. That doesn't make sense.

Dropped LU. Disassemble water pump. Looks fine. Impeller is nearly new.
Re-assemble water pump. Drop LU into bucket. Doesn't pump water with drill attached. Prime the water pump by pouring water into the exhaust port of the water pump and it moves plenty of water.

Re-attach lower unit. Start it up. Moves plenty of water. Then after a minute or so stops moving water. What the heck?

Dropped LU again. Put it in a bucket and attach drill. Doesn't move water. Prime the water pump. Moves plenty of water.

Why do I have to prime the water pump to get it to move water? Shouldn't it fill with water when the LU is submerged? I even tried to prime the pump with everything put together by pulling the cover to the thermostat and pouring water down there presumably to the water pump. But this didn't seem to do anything.

I know, replace the water pump. But this seems like an odd scenerio.

 

[Monte1961]

Re: 1963 18hp Evinrude water pump

The water pump/impeller are not self priming. Put it in a tank above water impeller and it should pump water. If not, theres other issues! Good luck and post back.

 

[ward cleaver]

Re: 1963 18hp Evinrude water pump

You know, soon as I posted this, I went out and took another look at things and somehow decided the thermostat was not opening or I havent been waiting long enough for it to open. So I amputated the thermostat. Pumps water like a s-o-b now.

I also figured out that the pump cant self prime because it never gets enough suction when drawing on air to pull in water to fill it up.

That thermostat is practically new. Shouldnt the water pump move water thru the pee hole even when the stat is closed/cold?

Anyway, I think I'll just run without it. Just let er warm up for 3 or 4 minutes before putting a load on it.