Evinrude 78 115 over heats even after new water oump kit installed

[scotty52]

Had new water pump and a seal associated with replacenent of kit. Motor wil run at low speed/idle +a little but when you push the throttle up the overheat buzzer goes off. Water passages blown and flushed out no joy. The motor runs strong and had no previous indication of problems.

 

[Daviet]

Re: Evinrude 78 115 over heats even after new water oump kit installed

Have you checked the temp with a temp gun, is it actually overheating, or do you have a sensor problem?

 

[boobie]

Re: Evinrude 78 115 over heats even after new water oump kit installed

As said above check with a temp gun first. If it is overheating you could have some thermostat or water deflector probs.

 

[scotty52]

Re: Evinrude 78 115 over heats even after new water oump kit installed

I was looking for some type of picture of diagram of the cooling system on the 78 115 Evinrude, also where is the overheat sensor located.

 

[Daviet]

Re: Evinrude 78 115 over heats even after new water oump kit installed

#35 is the heat sensor, located in the starboard cylinder head, it will have a brown or tan wire going to it.
http://www.ishopmarine.com/ishop/js...CatFilter=BRP&eCatSupFldr=supplier-100-005-EJ

 

[emdsapmgr]

Re: Evinrude 78 115 over heats even after new water oump kit installed

There is a temperature switch on each head. It will close (go to ground) and sound the horn when the cyl head temp gets to 212 degrees. The horn will silence when the cyl head temp gets back down to 175 degrees. (still too hot.) How long since the the two thermostats were replaced?

 

[scotty52]

Re: Evinrude 78 115 over heats even after new water oump kit installed

There is not a thermostat installed, was removed before I bought the boat

 

[emdsapmgr]

Re: Evinrude 78 115 over heats even after new water oump kit installed

There should be two thermostats and two nylon pressure relief valves in the thermostat housing for proper cooling. You can look at the original factory exploded parts diagrams for your engine at: epc.brp.com