Mercruiser Engine cutting off out of nowhere ( great to know stuff)

One day heading down the channel one of my engines Kept shutting off out of nowhere, you won’t believe what it was! With a little bit of luck we figured out what it was. Sometimes MerCruiser problems can be tricky especially with intermediate problems.
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[@user-ez8ko8tb4w]

Thank you very much for this suggestion! My port side cuts off for a second under way, along with the gauges so I will check this and also replacing start/ignition switch (370DA Inboards).

[@jimcatanzaro7808]

Buy the manual book for it u need to get rid of the stator first off and replace the seals for the water pump in the front of the motor

[@shanetyler9391]

Yeah mine will start and run at low idle when cold. then after running on the water for awhile when put into neutral it will die and not restart.i believe its a IACV idle air control valve.

[@gcalda62]

Mine dies after it’s warm, usually on the way out, just stops. Replaced ignition coil, still happens, only when warm, usually starts right up again, but only runs a few minutes, I’m thinking vapor lock? Online filter and water/fuel filter replaced… still no go, electrical or fuel?? It’s a 4.3 GMC OMC Four winns 1988 with 137 original hours

[@papicarta6387]

Did you ever find out the problem? Mine is now doing the same thing

[@codyjames8329]

Took it in salt water for the first time- came home and flushed it dies about 10 minutes in. Open the motor compartment and it’s smoking. No clue water was on it

[@hakansundberg1954]

I had the same problem but it was wrong with my killer switch

[@Cruisingthesouth]

😮 that can be tricky right! My safety switch is by my transmission so is a little more reliable than thous that hide behind the throttle handle

[@timothyhelf6144]

Had the same problem on 2 boats now, original fuse ir fuse block, very anoying

[@Cruisingthesouth]

I had a feeling that this happens a lot! You right sooo anoying it can be tricky to find the problem. My neighbor would’ve saved a lot of money if he had a 12v tester.. after replacing starter and alternator and battery figured it out that the alternator wire that charges the battery wasn’t connected! 😄

[@timothyhelf6144]

Yup, I bought one when we bought our first boat and made the difference between self sufficient, and paying people.

[@24rp84]

@@Cruisingthesouth hey

[@direstrait5418]

Hi, why do you have a cracked cylinder head? I have same engjnes.

[@Cruisingthesouth]

Hello my friend! What caused my cylinder intrusion was rust from the inside out. The cooling channel that passes by the exhaust port developed a pinhole, because my engines was raw water cooled before, and that won the battle. Now I have it fresh water cooled