Mercury 75hp cuts out

[alapmac]

1992 Mercury 75hp 3 cylinder outboard. Cuts out after 5 to 15 minutes, very sudden with no misfiring. Will start again the next day and do the same.
Replaced stator, trigger and power pack but still the same.
Any ideas?

 

[richardabeattie]

Is there an air vent into the fuel tank?

 

[alapmac]

I have run from different tanks. Also have no spark when it fails.
Thanks

 

[alan006]

A couple of things come to mind. You might have a poor electrical connection that when the engine gets warm is failing. The other odd thing that I heard of that caused an engine to fail after 10 minutes or so is the diameter of the fuel pipe.( Its not as barmy as it first sounds)
A chap had got a new outboard about your size and the engine kept dying on him after about 10 minutes or so and several people had tried different things but it turned out the fuel pipe was too narrow and it was fuel starvation!!!
Good luck.

 

[VicS]

[ QUOTE ]
Also have no spark when it fails.

[/ QUOTE ] Then it is an ignition fault. You have got to look at the bits you have not replaced already, including all the wiring especially connections. Ignition/kill switch ?

On the fuel front check for air leaks into the fuel line, especially the connector. Pumping the priming bulb would prove if that was the case. But it's not its near 100% certain that it is ignition.

A good place for advice on outbord problems is the iBoats forums where you will find a forum dedicated to Mercury and Mariners. If you go there be sure to quote the full engine details including model/serial number and year.

 

[Lakesailor]

Ring this guy. Marine Engine Supplies. He's on Hayling Island and what he doesn't know about outboard ignition isn't worth .....etc,

tel 023 9263 7700