Odd engine question...

While driving my boat the other day the following odd thing happened and my mechanic cannot replicate it.

Driving around 3000rpm (it is a 454) and all power dies (gauges, engine stop etc) and instantly turns over on its own in a 5th of a second from when it dies. I play with the throttle and it does not seem to be throttle related, when I made it to the marina we had to idle and when it powered off this time it was not turning enough to turn itself over again.

long and short is the follow

driving, engine turns off and on instantly (under load) while cruising

when at lower rpm when engine shuts off it will not start back up. no power to accessories either when it dies.

Thanks

check to see if the main engine harness plug is missing the clamp.

That sounds like it could be a short in the ignition switch.

Intermittent in main engine thermal circuit breaker on engine... or.. the fun one... a crummy connection anywhere in the battery to power/ignition switches engine wiring.