1975 Evinrude 70 hp Outboard thermostat ?

[G_dub66]

I have a 1975 70 hp outboard that starts like a champ and appears to have plenty of water coming out of the lower unit shifting is very smooth. I am afraid the head is getting too hot and am not sure how to tell if it is or not. After just a few minutes of running the outside appears to be rather hot and the water coming out of the lower unit is not barely luke warm. I would rather not replace a water pump if it is operational but how do you really know?

 

[Joe Reeves]

Re: 1975 Evinrude 70 hp Outboard thermostat ?

Test to see if the overheat warning horn is in effect. With the Key in the ON position, ground the TAN wire that is leading out of the cylinder head. The warning horn should sound.

If the engine overheats, the warning horn would sound before any damage can occur.

 

[kenmyfam]

Re: 1975 Evinrude 70 hp Outboard thermostat ?

I have a 1975 70 hp outboard that starts like a champ and appears to have plenty of water coming out of the lower unit shifting is very smooth. I am afraid the head is getting too hot and am not sure how to tell if it is or not. After just a few minutes of running the outside appears to be rather hot and the water coming out of the lower unit is not barely luke warm. I would rather not replace a water pump if it is operational but how do you really know?

How long can you keep your hand on the head when it is "hot"
Welcome to iboats

 

[G_dub66]

Re: 1975 Evinrude 70 hp Outboard thermostat ?

About 5-7 seconds but I am not sure I have left it on long enough to have the thermostat kick in.

 

[kenmyfam]

Re: 1975 Evinrude 70 hp Outboard thermostat ?

About 5-7 seconds but I am not sure I have left it on long enough to have the thermostat kick in.

That sounds O.K. but how long have you run it before you check. I run at idle for 10 minutes at least before I check.