3.0 tks mercruiser not staying running

[Eastc2415]

Recently purchased a 2006 tks mercruiser 3.0 that sat for about 3 years. The boat was professionally winterized prior to sitting and was looked at by a mechanic before I had purchased.

Since purchased I have replaced the following,

fuel filter
Fuel lines
Fuel pump
Carburetor
Alternator
Starter and solenoids
Fuses and breakers
Belts
Distributor and cap
Wires and plugs
Drained old fuel and replaced with new fuel
New impeller and gear oil and an oil change in the engine itself

since then I have hooked the boat to the muffs and still cannot get the boat the stay running. It starts but acts like it is starving for fuel or something and I know the carburetor is getting fuel, unsure if it’s needing configured or what. But if I throttle down the boat dies out and when started it runs about 20-30 seconds and dies.

any help would be great from here. I’m thinking maybe an oil pressure sensor or sending unit but I have no idea.

 

[todhunter]

Try running with the fuel cap off?

Check your anti-siphon valve?

 

[Eastc2415]

Yeah I have replaced both and tried as well and didn’t seem to change much

 

[Eastc2415]

Not sure how the oil shutoff works or the oil sending unit works or if that is a cause or could be but that’s the only thing I haven’t messed with