1997 Silverton 360 twin 502 XLI alarm and going to idle at 2200 rpm

[silverton360]

Have a Crusader 502 XLI that when running up the lake yesterday at about 3500 rpm, all the sudden got an alarm and engine went to idle. Oil pressure and temp was normal. Went the rest of the way to our destination with starboard eng at 2000. After our raftup, about 6 hours, started and headed back to dock, engine ran perfect for about 15 miles at 3500 then get the alarm and goes to idle. If I throttled up past 2200, alarm would go off and eng would go to idle. Again, oil pressure was normal as well as temp. Any ideas where to start? Sensor?

 

[Bondo]

Ayuh,..... Welcome Aboard,...... Scan the 'puter, the fault should be stored in it,......