Logo
FULL SITE MENU

71 Evinrude 60hp Lower Unit Cooling system

B

Bebor

New member
I Purchased a boat with a damaged lower unit. I found a rebuilt one on ebay with a warranty. My question is that the two units are the same except one thing on the impeller housing. My original lower unit had 2 holes where the copper pipes went up to the engine. One from the impeller (I assume to carry cold water to cool the engine) and one that I assume returns the hot water to the lower unit, and vents it back into the water. However my new lower only has the impeller hole open, and the return hole is closed. I am curious if this is simply a knock out, or if I can drill this out???
 
Two different cooling systems. The two-pipe system had a thermostat controlled recirculating cooling system. Water goes up one tube to and through the powerhead, then is presented to the thermostat. If too cool, it returns to the water pump for recirculation. When warm enough, the thermostat opens and water is discharged back to the lake and replaces with more lake water. This process goes on continually any time it is running, with 'stat opening and closing as necessary to maintain temperature.

The newer system does not have the recirculating feature, so only one water tube.

Are the two lower units interchangeble? I honestly don't know. Maybe somebody else does. But you do need to let it do its job as originally designed.
 
they are interchangeable all u do is change the water pump cover and the plate that the water pump rides on from your old lower unit I did it on my 1970 60 hp 3 cyl
 
Back
Top