1977 Evinrude 85HP - Running hot

[islandkiwi]

My 1977 Evinrude 85HP is running hot on cylinders 1 and 3. I've put in new WP and water is coming out the 2 rubber tubes at the back of the engine. There's also water coming out of tell-tale, but only sporadic.<br />I'm thinking of taking the t-stats out...Is thata sensible step or should I check something else first.<br />All input appreciated...

 

[Joe Reeves]

Re: 1977 Evinrude 85HP - Running hot

The OMC 1977 V/4 engines do not have a water telltale outlet. Do not run the engine without thermostats as that will result in piston damage.<br /><br />Remove the cylinder head that is runing hot in order to inspect the water deflectors that are located between the upper and lower cylinder and betwwen the bottom cylinder and the block itself.<br /><br />If the deflector between the two cylinders is swelled sideways, that causes a water restriction which will cause that bank to overheat. The cure is to replace the deflector(s).<br /><br />If the deflectors are okay, install a new thermostat.

 

[islandkiwi]

Re: 1977 Evinrude 85HP - Running hot

Hi Joe<br />Thanks for the reply. I'm even more confused. I've seen this motor running with water coming out of tell-tale. There's a rubber tube going from back of flat panel to tell-tale opening. The rubber tube is approx 30-40 cm long.<br /><br />Anyway, I opened the housing at back of cylinder, located at the base of engine. It's where the water from WP is going into engine. 2 springs came out with a melted white plastic substance, blocking the inlets for at least 85%.<br /><br />Are these the t-stats or is this something else.<br /><br />Cheers

 

[Joe Reeves]

Re: 1977 Evinrude 85HP - Running hot

If there's a water telltale outlet on that engine, it was either added on by someone or your engine is a later model. What is the model number of that engine?<br /><br />The thermostats would be the brass items in that assembly you dismantled. The other items you're speaking of (white) are the water bypass valve assemblies. Apparently the engine got hot enough at one time to melt them.<br /><br />That engine MUST have the thermostats and the water bypass valves installed in order to operate properly. Without them, the engine will run too cold, resulting in piston damage. Also the lack of those items will result in a loss of water back pressure which will affect the telltale outlet among other things.

 

[islandkiwi]

Re: 1977 Evinrude 85HP - Running hot

Thanks Joe. I've ordered the t-stats and bypass valves, Will install these this week...see if that fixed my problem.