Engine starts and shuts down

[Scorik]

Hello everyone. Please help a fresh captain. Mercruiser 5.7 LX carburetor engine. It starts and almost immediately, after a few seconds, it shuts down. What could it be, where to start the troubleshouting??

[mmwjr]

What year is it? 1998 and newer uses an electric fuel pump which gets power from the starter solenoid when starting and a oil pressure switch once started. Most likely the oil pressure switch is bad. See the Mercruiser manual for your engine under Documents. The switch is located on the rear port side of the engine next to the oil filter adapter connection on the engine block.