Mercruiser 5.7 Momentary Engine Cutout

[iaff284]

I have a 1995 Crownline 225BR with a carbureted 350 Mag engine, Thunderbolt V ignition with knock sensor, and an Alpha 1 Gen II drive. I have an occasional situation where the engine will act like the key has been shut off for a split second and then immediately return to running fine. This occurs when cruising at speed. I rebuilt the engine, carburetor, replaced the fuel pump, and replaced the plugs, rotor, cap, and wires two years ago and it ran fine for the first year. Then this momentary cutout started last summer and would happen once or twice during an outing. This summer the cutout has become more frequent along with a hard start condition when both hot and cold. Any help is appreciated.