55hp Evinrude alarm

[Arnold Brouwers]

I have a 55hp Evinrude, model no. 55979C, serial no. A348167 - I've been told it's a 1979 model. First trip out a year ago, it ran fine for maybe an hour running at medium speeds. Then after slowing to an idle for about 10 minmutes, an alarm sounded. Stopped, checked and then decided to make a run for the ramp. After a minute or two at higher speed, the alarm stopped.<br />I have since had the thermostat & impeller replaced and disconnected the wire from the sensor (while the alarm was sounding) to rule out a short in the horn. Then I thought maybe because I was running in shallow water that I was sucking up too much sand & silt - I paid particular care to this & while it seemed to help a little, the alarm still sounded. I recently hooked up an OHM meter to the sensor (engine was cold) - that showed some continuity between it and the engine ground but I don't know if this proves that the sensor is faulty.<br />The alarm has sounded after only 5 minutes but last trip I was running at medium to high speed for 50 minutes before it went off. When it did, I could still touch the head but only for a second or two. It's only sounded when on the water and never at home even after extended running.<br />I'd really appreciate any feedback.

 

[Dhadley]

Re: 55hp Evinrude alarm

Did you change the housing and plates when you changed the impeller? How much water pressure do you have at WOT?<br /><br />Good luck!

 

[Dhadley]

Re: 55hp Evinrude alarm

OH -- and how about the head gasket? Since we know it has been hot it needs to be changed now anyway.<br /><br />Good luck!

 

[Mike M2]

Re: 55hp Evinrude alarm

Do you mix oil? if it's a VRO it could be oil sending.

 

[Arnold Brouwers]

Re: 55hp Evinrude alarm

Thanks for the speedy response Dhadley.<br />Housing and plates weren't changed with the impeller. I don't know what a WOT is. But if it's the tell-tale, then there has always been a good strong flow from that with the water warm but never hot.<br />The head gasket was changed when the thermostat & impeller were done.<br />Does anyone know if there's a quick & cheap way of tacking a heat sensor onto the head to check if it's really overheating?

 

[Arnold Brouwers]

Re: 55hp Evinrude alarm

To Mike M2, yes I do mix oil so I don't think it's an oil sending alarm. I use a 50:1 mix.

 

[Dhadley]

Re: 55hp Evinrude alarm

WOT is wide open throttle. Start with the completion of the water pump job. Housing and plates. Retorque the head (at least) if you won't change the gasket. How much water pressure (on the gauge) do you have?<br /><br />Good luck!

 

[clanton]

Re: 55hp Evinrude alarm

Tan wire on sensor should NOT show continuity to ground with cold engine. Remove temp sensor put in hot water, switch should close at about 203 degrees fahrenheit. Water passages in head may have silt and sand in them.