I have a 2001 Mercruiser 5.7 Bravo 3 with single barrel carborator. When the engine warms up about 10 minutes it wants to stall as if it's out of fuel. Runs extremely rough until it stalls. This is intermittent and doesn't occur all the time. Normally if I let it set a minute it will restart and it may continue to run fine or it may stall a few minutes later. I thought this only occured when I was idling through the canals but it also will do it at full speed. Also my rpms are about 400 less at full speed when it is running. At full speed the engine dies immediately. This is intermitent and only when the engine is up to temp.
Things I've done:
Cleaned the carborator with spray carb cleaner. It had buildup and the choke was quite sticky. There is a linkage on the right side that connects to the choke that is a little stiff still even though I put some oil on it. Still a bit sticky.
There is fresh fuel in the tank, 50 gal, from a marina with no ethynol. I added 3 cans of fuel additive thinking about moisture in the fuel or something else gumming up in the carb.
I ran it full speed for about 30 mins where it stalled suddenly about 3 times. RPMs were about 400 lower when it is running. I pulled the fuel filter which is the size of an automotive oil filter, dumped it into a jar to look for water. Fuel looked pristine however when I checked this the engine happened to running ok.
About 8 months ago the manifolds clogged and blew a head gasket. The engine was pulled, replaced head gasket, manifolds, valve job. Don't know if there could be any relation. It ran well after the repair until about 4 weeks ago.
It feels like one cylinder may be missing. It's an 8 so hard to tell if it's missing or something else is going on.
I'm thinking about two things: a complete rebuild of the carb as well as drawing fuel out of the tank looking for water. Maybe intermittent problem with the fuel pump. But since this only happens when the engine is hot I'm thinking carborator.
Is there anything electrical/ wiring I should be looking at?
Any help would be greatly appreciated.
Things I've done:
Cleaned the carborator with spray carb cleaner. It had buildup and the choke was quite sticky. There is a linkage on the right side that connects to the choke that is a little stiff still even though I put some oil on it. Still a bit sticky.
There is fresh fuel in the tank, 50 gal, from a marina with no ethynol. I added 3 cans of fuel additive thinking about moisture in the fuel or something else gumming up in the carb.
I ran it full speed for about 30 mins where it stalled suddenly about 3 times. RPMs were about 400 lower when it is running. I pulled the fuel filter which is the size of an automotive oil filter, dumped it into a jar to look for water. Fuel looked pristine however when I checked this the engine happened to running ok.
About 8 months ago the manifolds clogged and blew a head gasket. The engine was pulled, replaced head gasket, manifolds, valve job. Don't know if there could be any relation. It ran well after the repair until about 4 weeks ago.
It feels like one cylinder may be missing. It's an 8 so hard to tell if it's missing or something else is going on.
I'm thinking about two things: a complete rebuild of the carb as well as drawing fuel out of the tank looking for water. Maybe intermittent problem with the fuel pump. But since this only happens when the engine is hot I'm thinking carborator.
Is there anything electrical/ wiring I should be looking at?
Any help would be greatly appreciated.
