Re: 92 4.3 merc shuts down at will
When you mean shut down it just stops running?
And when you try to start it, do you mean the engine cranks but doesn't start?
Alot of things you can do that won't cost a dime, but will take time.
When it happens do you pull a spark plug and ground it to the block to see if you have spark?
If spark is present is it a good spark.
Gas going to the carb? Take off the arrester and see if gas shoots when you advance the throttle.
Now to what you can do, Have a tester on the boat like the one in the thread i will post.
But you can clean the filters, There is one in the fitting that goes into the carb, one maybe in the fuel pump, one in the fuel pickup tube in the gas tank, And the water seperator. Take it off the filter and dump in a clean clear,container.
Let it sit and see if theres alot of gunk and water in the gas.
And clean all the connections with the battery cables off. Neg first than pos.
This way when it happens again hopefully not, you will know it's not the cable for example.
Heres the post from the master Don S:
http://forums.iboats.com/showthread.php?t=167035
Another way would be to run the boat on a external tank of gas to rule out any possible gas related problem. After you cleaned all the filters.
Another point the carb cleaned last when?
You see it might not be that when it cools down that lets you start and run, but the filter gets clogged and restricts the fuel than shuts down the motor.
You wait the sediment comes off the filter and it starts and does it over again.
