I have a Trophy 2359 Hardtop and the warning alarm beeps regularly twice every minute after planing for about 15 minutes. Everything checks
The oil, temperature and gear lube are all fine. The dealer has had it in and hasn't fixed it. I have it in there again right now but they seem unable to deal with it.
Thought you were here
Try using throttle body cleaner to clean the IAC (Idle Air Control Valve); Also, a hot spot in the engine could cause pre-ignition and set off the knock sensor: how old is the cooling system and has it been serviced.
Third, vibrattion can set off a sender. Is the engine and all bolt-on accessoris tight?
Your tech oughta be able to narrow this down with a scan tool/ Are you dealing with an authorized Mercruiser mechanic?
I am here now. Yes, I have the boat in with the dealer I purchased it from. I will copy the replies you have provided and give them to the tech if they can't solve the problem. I thnak you!