Mercruiser 4.3 TDK Alpha stalling

SteveTahoe

Cadet
Joined
Jul 17, 2011
Messages
7
Ok, I know this problem has been reported on her a thousand times, but the thoughtless authors never come back and post the resolution for the next guy.
I bout this boat in 2009, this is my third season. It has a carbuerator. After dewinterizing, it started up fine. 1st day on the water it ran fine for a couple of hours, then suddely stalled. It took a few minutes to start up again but it ran well for awhile longer and stalled again. Back in my driveway I put in some WaterZorb and it seemed ok. Back on the water, same scenario as 1st time out. Back in the driveway again, I siphoned out the old fuel and refilled using 93 octane and a marine fuel additive. This was done by the suggestion of a friend who thought last years stabilized fuel was bad. Nope, still stalls. I checked the fuel/water separtor, no water present. At first, it starts up fine, then stalls when I shift into gear. Then it becomes more difficult to start and I usually have to engage the throttle to give it more gas. Then it will rev high for awhile then either stall out, or it will stall when I put it back in neutral. If it doesn't stall in neutral, it idles very low and rough for a minute, then stalls. I should probably add this although it may be a separate issue: this engine has always had a problem of continuing to run after I shut it off, usually for 10 seconds until it putters out. Thanks in advance for any guidance.
 

Pete104

Lieutenant
Joined
Apr 30, 2011
Messages
1,439
Re: Mercruiser 4.3 TDK Alpha stalling

Have you considered a tune-up + carb rebuild?
 

starsnstripers

Lieutenant
Joined
Nov 30, 2007
Messages
1,330
Re: Mercruiser 4.3 TDK Alpha stalling

(if applicable) Did you check the filter/screen at the carb? Also anti syphon valve can stick and restrict fuel flow.
 

SteveTahoe

Cadet
Joined
Jul 17, 2011
Messages
7
Re: Mercruiser 4.3 TDK Alpha stalling

I didn't think of a tune-up or carb rebuild, I've only had it for 2 short seasons. Also didn't check either the filter at the carb or the anti-siphone valve, will do so in the morning. Thank you both.
 

SteveTahoe

Cadet
Joined
Jul 17, 2011
Messages
7
Re: Mercruiser 4.3 TDK Alpha stalling

Going out now to test a few things...any chance it's the fuel pump or the coil?
 
Last edited:

SteveTahoe

Cadet
Joined
Jul 17, 2011
Messages
7
Re: Mercruiser 4.3 TDK Alpha stalling

Ok, it's not the carb filter and the anti-siphon valve is clean and moving as it should. Not sure if I know how to test the fuel pump, but I'm sure I can find instructions on testing the coil.
 

SteveTahoe

Cadet
Joined
Jul 17, 2011
Messages
7
Re: Mercruiser 4.3 TDK Alpha stalling

Carb rebuild, $250, you called it Pete. Thanks to all who responded.
 
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