Boat ran fine then just died

[Jaymoney412]

I was cruising in my boat yesterday and all of the sudden the engine quit tried restarting it started then died again tried to start a few more times same thing I got it home changed fuel filter and now it wont start at all just cranks please help I am looking all over the internet and there are so many things it can be I dont know where to start I am new to boats and this is my first one the boat is 88 tinker 195 with a mercruiser 4.3 lx with thunderbolt ignition I had the boat cruising at 4000 rpms 3/4 throttle for about 45 minutes before it died out I did have it wot for a few mins here and there but rpms never went above 4800 temp was fine oil pressure was fine I dont know where to start please help

 

[Bt Doctur]

Got gas in the tank?

 

[Jaymoney412]

Yes 35 gallons

 

[Rick Stephens]

Being an 88, it might not have a canister type water separation filter, but if it does, then it may need to be filled up to help prime it. Also, there is a filter on the inlet fitting at the carburetor on most models. That could be plugged up.

 

[Jaymoney412]

Thank you I will check that when I get home and the separator was changed

 

[nola mike]

1. Check spark. 2. If spark, pour a little gas down the carb throat and see if it catches.

 

[wellcraft-classic210]

I usually start with determining if its a fuel or spark issue when an engine wont start--

If its fuel a little gas down the carb or starting fluid will usually get the motor to start & run for a short time // fuel squirting down the barrels from the accelerator pump when throttle is moved ins another indicator.

Clogged fuel filters are the first place to look followed by fuel pressure checks // If their is debris in a fuel tank ( not uncommon ) it will can stirred up at high speeds & flows and tend to show up in unwanted places such as fuel filters

Spark requires pulling a wire and attaching it to a grounded spark plug or similar. I keep an old plug ( or a spare set ) on board just in case.

 

[Jaymoney412]

Ok so I have fuel replaced plugs boat starts but does shortly after tested wire coming from coil with sparkplug light and it was lit from start up then flickered before stalling would that mean my coil is bad?

 

[Jaymoney412]

Sorry does =dies

 

[nola mike]

Sounds like a fuel issue. If it runs for a few seconds after you prime it, money's on needing a carb cleaning (assuming clean /changed fuel filters and fresh gas).

 

[aviationMx]

My 305 was tooling along last season and suddenly died, after waiting for 2 hours for seatow, I found the low voltage connector on the coil had broke.

 

[nola mike]

His restarts and has spark.

 

[aviationMx]

Missed he's got spark.

 

[kulle]

could it be the oil pressure/sender switch ? If that fails, it will not send 12V to the fuel pump( if electric). I had that same problem, boat would fire up only run for 30 secs maybe and die. About a $30 part and was port side of merc 4.3L.

 

[derfxa]

After failing to restart, with air filter off, look down the carb and if gas is ponding it's flooding If so, disconnect the fuel pump electric leads, then try starting with minimum throttle and if it starts reconnect the fuel pump. That indicates there's an issue with the carb or fuel pump.

I have a 4.3LX and I have been wrestling with having an older carb and a newer fuel pump (had flooding, not restarting problems). I balanced out the fuel pressure, using an older carb help with a fuel pressure regulator in-line between fuel pump and carb. BTW-(try the full throttle, when starting, trick to get a flooded merc started - older mercruiser technique).

 

[havoc_squad]

I have a 4.3LX and I have been wrestling with having an older carb and a newer fuel pump (had flooding, not restarting problems).

I balanced out the fuel pressure, using an older carb help with a fuel pressure regulator in-line between fuel pump and carb. BTW-(try the full throttle, when starting, trick to get a flooded merc started - older mercruiser technique).

Did you verify that you were using the correct gasket part # with mechanical fuel pump?

Some people either order a fuel pump that comes with the gasket without verifying gasket part # or they order the wrong gasket.

Majority of the cause of mechanical fuel pump over pressure is due to too little of distance from pump to engine block, caused by wrong gasket for different motor.

I believe for certain GM engine models used in boats, the same mechanical fuel pump is used but different gasket having different thicknesss for each motor.

Regarding OP's issue, if putting a small amount gas down the carb ports with throttle opened a small amount (high idle) and it briefly starts and runs but dies, I would first check fuel pressure, then if that checks out, I would dig into the carb.

After three attempts of priming intake with gas and getting it to run briefly and you don't have fuel pressure on fuel gauge to carb, I would say your fuel pump is toast or you have large fuel flow obstruction or restriction in the fuel line to the fuel pump.

 

[derfxa]

Electric fuel pump is used for 1995 4.3 LX Mercruiser

 

[Jaymoney412]

I have fuel its the ignition I have issues with and I believe it is the coil I will repost after I replace it