The engine stalled and no start while on the water

[Gerhard Peters]

Took my 1995 Bayliner boat with the 4.3 Vortec Mercruiser engine out on the water today and after a while of boating the engined stalled. It would not start again. Had a good samaritan tow me to shore. After loading the boat on the trailer and coming home the engine is starting again. While on the water I checked and it had fuel and the engine oil level is fine too.

I replaced the engine myself in 2019 and it has worked fine until now. This is the first boat I ever worked on.

Where do I start with this intermittent issue?

 

[alldodge]

What ignition system does it have?
Have you check the kill switch?
When key is tuned ON is there 12V on the + side of the coil?

 

[Scott Danforth]

start at the battery and work your way up the wiring all the way to the helm. clean and tighten every connection.

 

[Bondo]

Ayuh,..... Was it turnin' over, 'n not starting, or just plain dead,..??

 

[nola mike]

Start with spark, move on to fuel... Which are you missing when it won't start? And assuming you mean it won't run, not won't crank

 

[Gerhard Peters]

Correct it was turning over (cranking) but the engine would not start. It is not the kill switch. I tried turning it on and off. Unless the kill switch could be an intermittent issue.

Before replacing the engine it has the thunderbolt ignition system (which did not work) but I replaced it with the Sierra Marine Delco EST Conversion Kit distributor.

One thing I did not check after it would not start is if it was overheating.

As far as I know, the engine will stall when it is overheating and if so how does that work? It has 2 temperature sending units and I'm assuming that one is for killing the engine when it overheats. This is something I would like to know more about in case it was overheating and that made the engine stall. I forgot to check in temperature gage after the engine would not start

 

[San_Diego_SeaRay]

Correct it was turning over (cranking) but the engine would not start. It is not the kill switch. I tried turning it on and off. Unless the kill switch could be an intermittent issue.

If it does turn over, my suggestion would be to get a can of starting fluid and spray some in carb then try turning the engine over. If it sounds like it wants to start more than it previously did w/o the fluid, then it sounds like you have a gas delivery problem. If there is no improvement, I would move on to diagnosing an ignition problem, which includes a killswitch.

Regarding the overheating, you'll have to get the engine started to determine if that is really an issue.

 

[Rick Stephens]

If it does turn over, my suggestion would be to get a can of starting fluid and spray some in carb

Skip the ether on a gas engine. Good way to blow a head gasket or do other damage. Just takes good diagnostics without risking your motor. As noted above, find out if you have spark and if not the problem, where the fuel problem is.

 

[Gerhard Peters]

Does anyone know if the temperature sending units can disable the ignition system when say the engine overheats? Why does this 4.3 have two temperature sending units?
Where can I get a wiring diagram for my boat?

 

[nola mike]

Correct it was turning over (cranking) but the engine would not start. It is not the kill switch. I tried turning it on and off. Unless the kill switch could be an intermittent issue.

Does anyone know if the temperature sending units can disable the ignition system when say the engine overheats? Why does this 4.3 have two temperature sending units?
Where can I get a wiring diagram for my boat?

No, if your engine stalls because of an overheat it's because you're damaging something. One of the senders is for the gauge, the other should be for the alarm if equipped.

 

[Gerhard Peters]

Ok so the alarm would sound if the engine was overheating...correct? Same if the oil pressure was low...correct?

I have the alarm system

 

[nola mike]

Ok so the alarm would sound if the engine was overheating...correct? Same if the oil pressure was low...correct?

I have the alarm system

If they're working, yes