1991 Merc 4.3L Intermittant stalling

jallen100

Seaman Apprentice
Joined
Mar 20, 2011
Messages
37
My boat will stall intermittantly and will be hard to start afterwards. Its pretty odd and usually happens in shallow water when idling. It will stall and then not start for 10 min or so. Usually if i let it sit then it will fire right up. I can shut it down 2 or 3 hours later and then fire it right back up with no problem. It just happens every once in a while but it is pretty fricken awful when it happens while I am waiting to load up and then I am powerless at the docks with 10 other boats circling around while waiting. I almost beached it on rocks this weekend when it happened. Any Ideas?
 

mkast

Lieutenant Commander
Joined
Nov 6, 2002
Messages
1,934
Re: 1991 Merc 4.3L Intermittant stalling

Have you completed any troubleshooting?
 

jallen100

Seaman Apprentice
Joined
Mar 20, 2011
Messages
37
Re: 1991 Merc 4.3L Intermittant stalling

Have you completed any troubleshooting?

New cap and rotor has new wires and supposedly new plugs at the end of last year. I just bought the boat in Feb and the previous owner had all of the above done.
I had my mechanic clean the cap and rotor, I ran some fuel cleaner through it. My mechanic lowered the idle a little which I have a sneaking suspicion that he may have taken it a little to low but I am not 100% sure. The carb looks nice and clean by looking inside. It does seem that it should start a little easier than it should. It takes a couple trys sometimes but then the next time I go to take it out it fires right up on the first shot.
 

dubs283

Vice Admiral
Joined
Jul 27, 2005
Messages
5,058
Re: 1991 Merc 4.3L Intermittant stalling

upon shutdown, check to make sure the carb is dry, no fuel running down the throats

also, feel the coil, is it very hot to touch??
 

mkast

Lieutenant Commander
Joined
Nov 6, 2002
Messages
1,934
Re: 1991 Merc 4.3L Intermittant stalling

Troubleshooting is not part replacement.
You can replace parts until you go broke or bump into the problem.
Do you have the Mercruiser maintenance manual?
 

jallen100

Seaman Apprentice
Joined
Mar 20, 2011
Messages
37
Re: 1991 Merc 4.3L Intermittant stalling

Troubleshooting is not part replacement.
You can replace parts until you go broke or bump into the problem.
Do you have the Mercruiser maintenance manual?

I do not have a manual. I went to the marina a couple weeks ago to get one and they were sold out. They still dont have one in.
 

jallen100

Seaman Apprentice
Joined
Mar 20, 2011
Messages
37
Re: 1991 Merc 4.3L Intermittant stalling

upon shutdown, check to make sure the carb is dry, no fuel running down the throats

also, feel the coil, is it very hot to touch??

I will check this weekend when we go out.
 
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