New to the sight so thanks for having me. I have a 2012 Bentley with a 90hp EFI Merc four stroke. Here's the low down on an issue I'm having. The guardian alarm goes off sometimes shutting down the motor. The alarm is the 3 to 5 sec straight alarm, not the short beeps. After unwinterizing the motor (lower unit oil change, fresh fuel, hooking up battery), the motor started and ran great as it has every year. Cleaned the toon up and went to the lake a week later. Started up at the dock, was slowly leaving the no wake zone when the alarm went off for 3-5 secs. I backed the throttle to nuetral and after a few seconds the motor shut off and would not start. Got towed back to the dock, put the boat on the trailer, started the motor and it ran. Went home and viewed the Mercury guardian alarm codes and found that (3) things cause the long beep. 1. Oil level. I went right out and changed the oil and filter. It was done last season and I put about 30hrs on the boat, but did it anyway. 2. Overheating. Ran the motor with muffs again and had a water stream, but thought maybe is was getting weak under load. Did an impeller change last weekend, great water flow. 3. Low voltage. Re-charged the battery. 12.7 reading of the battery alone, 13.7 battery reading when hooked up to the boat and running.
Went back to the lake. Ran up and down with no issues or alarms. Sat at a cove for about 2hrs for lunch with radio on. Let cove, alarm came on, motor shut off. Waited for 15mins, re-started the motor, ran and went back to the dock. One thing I noticed was the RPM guage was bouncing around after it re-started, but the motors RPM's were steady and not bouncing. I'm pretty mechanical for working on motors, but don't know where to start now. I don't trust taking it out with the issue being intermittent. Any help is appreciated, marina can't see me until Aug 17th
