225 HP alarms and drops to idle while operating

My boat has a pair of 225 hp Honda outboards. On an intermittent basis, the starboard motor alarm will chime and the motor will drop to idle. The motor then runs very rough if I try accelerate it. The motor runs normally (until the next time) if I turn it off and restart it. No codes are stored.

Does anyone have any ideas?

What year is the engine? Or serial number? If you have the four-light key switch, are any of the red lights coming on? Are any of them blinking? Is the green oil pressure light staying on?

There is only two conditions where the engine will automatically drop down to 1800 rpm's - overheat, where it will run for about another 20 seconds then shut down, or low oil pressure, where it will drop to 1800 rpm's but keep running.

Are both engines coming off the same tank with a common pick up and common fuel feed to the external fuel/water separator?