1977 25HP Evinrude temperature

[Randyg123]

A friend was telling me that his tell-tale is sometimes cold and sometimes too hot (to the point that he is careful about just sticking his hand in the stream to check temp). That didn't sound right to me. I asked him if he'd checked the thermostat and his reply was that he didn't think that model even had one. I told him it did.

What is the "Hand on the cylinder" rule for quickly assessing engine temp.

 

[ezeke]

Re: 1977 25HP Evinrude temperature

You should be able to keep your fingers on the cylinder head for a full three count any time the engine is running.

The 143? F. thermostat is found at the top of the cylinder head behind the water cover. The thermostat opens to allow the water to pass out of the cooling passages when the engine water reaches around 143? F. If the water coming out is too hot to touch, the thermostat is malfunctioning or the water passages in the engine are overly restricted in some way.

Edit: That does not mean to imply that 143 degrees is safe. The three second rule should apply; half a minute in water at 130? F. will result in third degree burns. See the chart here: http://www.antiscald.com/prevention/general_info/table.php

 

[Randyg123]

Re: 1977 25HP Evinrude temperature

Thank you