Mercruiser 4.3 stalls at full throttle

M

mkfs9

Seaman
Joined
Jul 8, 2005
Messages
64
Back from holiday skiing and cruising around. then on the last day decided to open her up and she just seemed to be starved of fuel at wide open backed off and it picked up. Runs perfect the rest of the time , have owned this 1988 boat from new and never had any think like this before. Any help would be great thanx
 
M

mkfs9

Seaman
Joined
Jul 8, 2005
Messages
64
Re: Mercruiser 4.3 stalls at full throttle

Must add just had lower shift cable replaced, wonder if its the micro switch cutting in because it does not splutter just seemed to cut out at full throttle, Mmm
 
spdracr39

spdracr39

Lieutenant Junior Grade
Joined
Aug 30, 2010
Messages
1,238
Re: Mercruiser 4.3 stalls at full throttle

Change your water sep filter and fuel filters. Also you could check the fuel pickup screen in the tank for any blockage. Doesn't take much to starve for fuel at WOT. If all that checks out it might be the float is set to low running the carb out of fuel.
 
M

mkfs9

Seaman
Joined
Jul 8, 2005
Messages
64
Re: Mercruiser 4.3 stalls at full throttle

Thanx for that. I have no fuel/water filter but did check the one on the carb and it looked perfect. coulg be the the float then its never been adjusted ever to my knolledge. as said runs perfect except that last 10% of throttle.
 
ktbarrentine

ktbarrentine

Lieutenant
Joined
Dec 12, 2011
Messages
1,296
Re: Mercruiser 4.3 stalls at full throttle

Agree on the possibility of the float.... While your checking that, how about a full carb dip and rebuild? How long since its been done on this 88? How many engine hours? I love carb rebuilds... kinda therapeutic. And if really needed and done right, the results are tremendous.
 
G

generator12

Senior Chief Petty Officer
Joined
Jul 9, 2010
Messages
666
Re: Mercruiser 4.3 stalls at full throttle

I would tee a pressure gauge off the fuel pump to see if you're maintaining normal pressure. If so, look into the carb. If not, look upstream of the gauge. (Fuel filter, pump, fuel tank vent, etc.)

Helps eliminate the guesswork.
 
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