How does the water cool the engine ?

[csaba]

We have an old 1973 Johnson 65 HP outboard ... (65ESL73R)<br /><br />We changed the impellor but we noticed that water was coming out of the water pipe that goes up from the water pump to the engine. We took this pipe off and noticed that there was a small hole that was drilled into the pipe. Why do they have this ? Is there supposed to be water in the middle section ? Also the water that came out of the engine went directly into the middle section ? There are 2 holes in the casing where I thought the water was supposed to go out but there's nothing connecting these holes to the motor where the water comes out ? Why does the water go into this middle section and is it normal ?<br /><br />I'm lost on how this works ???

 

[oldboat1]

Re: How does the water cool the engine ?

I'm not aware of any design that involves a whole in the water tube running up from the pump to the powerhead. The water that exits the exhaust ports on the rear of the leg comes down into the housing from the powerhead with the exhaust, and some of it spurts out of the exhaust ports. Most of it exits through the hub in thru-hub exhaust models. A repair manual for you motor will show you specifically how the water circulates through the engine.<br /><br />Maybe some of the technicians can correct me on the hole-in-the-tube issue. It sure doesn't look like any design feature to me.