I have a 1997 Bayliner Mercruiser MCM 5.7 EFI Alpha I Gen II Drive - Engine Serial # - 0K007818. We were heading back to the dock yesterday after being out on the river all day. We were cruising at about 3800 RPMs and had been underway for about 15 minutes when a long beep sounded and the boat slowed down on its own (the guardian?). I had no clue what was going on but I quickly pulled the throttle back to idle. All the gauges appeared to be normal, no smoke or odd noises to speak of. After sitting for a minute, I put it back in gear and started moving at about 2000 RPM and it wasn't more than 30 seconds and the boat beeped again but this time without the reduction in power. I could see the dock at this point so I throttled down even more and we never heard the beep again. Pulled the boat out and I came back home and started looking around the internet and figured out that the alarm signals 1) low drive lube 2) oil pressure and 3) engine overheating. The drive lube is full, the oil gauge was at 40 (right in the middle) and I don't know about overheating. I just replaced impeller and housing last week and new fuel filter but that is pretty much the extent of my repair history thus far. I am a new boat owner so I need guidance in where to start when troubleshooting an overheating issue??
