Merc 80hp shuts off

[dmtrower7]

I just got my 1989 merc 80hp running today, and when I went full throttle, it shut off. Turned the ingnition off and back on, it re-started. Went to slower speed and in a few minutes, it shut off again. Motor ran well at full and mid throttle. Is there a temperature or oil sensor that can shut off the motor during operation? If so, where is it located? Motor idled well all the way back to the dock. Thanks!

 

[Laddies]

Re: Merc 80hp shuts off

There is no fail safe shut down on your engine

 

[Chris1956]

Re: Merc 80hp shuts off

Check to see that your fuel filters are clean, and the vent on the gas tank is clean. It sounds like a fuel restriction issue.

 

[Texasmark]

Re: Merc 80hp shuts off

Had a boat with a BI fuel tank. Always worrying about fresh fuel. Used the water absorbant type fuel conditioners.....assume alcohol based.<br /><br />What happens (happened) is (was) that when alcohol comes in contact with water in your fuel system it makes a milky jelly goo.<br /><br />Well one day I was blasting across the lake and the engine just died. In short, I trouble shot the fuel system and line all the way to the fuel line side of the fuel inlet connector (had to break the SS band holding the line onto the connector) that attaches to the engine and lo I find the fuel line is plugged with this goo; which I also found many years later in my truck's windshield washer squirter when I used to dilute the blue washer fluid with water. <br /><br />Used the squeeze bulb to flush the goo and fuel thru the line and freed the line, reconnected it to the engines mating connector and end of story......but no more water absorbing stuff went into my fuel tanks.<br /><br />So might depress your springloaded valve where the fuel line connects to the motor (wooden popsickle stick works great) and squeeze the prime bulb till you have squeezed out a quart or so of fuel into a container of some sort.....if the other suggestions don't solve it.<br /><br />Doesn't sound like your problem is electrical and if the whole engine shuts down at a high fuel consuption rate.....it is an "engine" supply problem.<br /><br />HTH<br /><br />Mark

 

[dmtrower7]

Re: Merc 80hp shuts off

Thanks for the input, but I believe it to be an ignition problem. The reason I believe this is that the engine just "shuts off", no slow dying, just wide open (or mid throttle) to off in an instant. Fuel seems to be fine (new fuel pump, cleaned carbs, good flow from the tank to the carb inlet) I was considering that it might be the mercury switch (after reading the manual). Any thoughts? Thanks again for all your help.

 

[Laddies]

Re: Merc 80hp shuts off

Remove the blk/yellow wire from the switch box, that is the ground off wire and try the unit to see if the trouble is in the engine or wiring harness