1990 70hp Evinrude shuts down

[Silvio]

My 1990 70 hp Evinrude shuts down after about 5 minutes of runtime and will not start up again unless I wait another 5 minutes. Any ideas on whats causing this?

 

[emdsapmgr]

Is the engine overheating? Does your hot horn work in the control box?

 

[Silvio]

The horn works it went off the first time it happened but not again since. I put in a new power pack which didnt help. I timed it. the boat runs for 3 1/2 minutes at an idle before it shuts down, not sure thats long enough for it to overheat. Also if it overheated in the past it would drop the speed not shut it down completely. Seems to be pumping plenty of water.

 

[Silvio]

Also the boat was oil injected, but was switched to just mixing the oil about 3 years ago, and I have not had a problem with that.

 

[emdsapmgr]

It still could be overheating. Just because you have a strong telltale does not mean that water is circulating through the block and out the exhaust. You could have a stuck/restricted thermostat. How long since it was replaced? When the engine shuts down, does the engine block seem "locked up" for a short period of time?

 

[jakedaawg]

Why not just do a spark check as soon as it shuts down.

 

[fireman57]

When it starts up again does it run the rest of the day with no problem or shut down again? If it keeps shutting down make sure your tank is vented.

 

[Silvio]

The thermostat is not in it so no restriction there. There is no spark after it shuts down. Tried different fuel tanks and lines, not a fuel problem, definately electrical because its losing spark.

 

[jakedaawg]

Goto cdi electronics and use their trouble shooting guide when it has no spark.

 

[flyingscott]

You need to put the thermostat back in so it can warm up properly.

 

[Silvio]

The motor will not run with the thermostat in it has been like that for over 15 years. The overheat alarm goes off every time you put the thermostat in. I will try the CDI troubleshoot guide thank you

 

[fireman57]

If it won't run with the tstat in then it is overheating. You probably have calcium buildup or some other gunk in the water passages. I would do a compression test first to make sure you have an engine to fix.