2006 LF 115 TXR 50 hr total

[LGHaag]

Eng. runs for 10-30 min. depending on RPM (3400 to 4000). Thereafter cuts out to idle, and up to 1500 RPM but not higher.
After cooldown (Next Day) Runs fine again for 10-30 min. thereafter same problem.
Have checked Fuel filters, coolingwater outlet and diconnected temp sensor. (Eng. is not running hot) Replaced ECU and Rectifier without result.
Can you identify sensors who can cause the eng. to go down to emergency mode. Please Help

[boats.net]

Overheat and low oil pressure will activate warning system warning buzzer will sound and reduce rpm's to 2000 rpm's.
Check buzzer by disconnecting landyard cord and try to start, buzzer should sound.
Probably need to have compression test, fuel pressure test run and checked with computer diagnostic.