40 hp Mariner

I just got a 16 foot jon that has a 40 hp, 4 stroke, 1995 Mariner Magnum with a steering wheel and throttle control console, electric start. Took it out for the first time and had it running WOT for about 15 minutes when something started beeping. It sounded like it was coming from the console but I'm not sure what caused it. I backed off the throttle and it stopped then started again a little later. Any ideas to what would cause an alarm like that?

Not sure on 4 strokes. On a two stroke a beep beep beep is low oil in the reservoir, while a steady beep is an overheat alarm.

Did some research...it's actually a two stroke with oil injection. Changed the impeller for good measure but the beeping continues. It starts after I've been on the throttle hard for a while. Short beeps on about 20 second intervals but sometimes it's a very weak beep, almost like a scratching sound. Any ideas what the problem could be? Thanks.

Well obviously it's sending a signal to the ignition ready / oil-overhead chime. Do you have a point and shoot thermometer to get some temp readings and see if it's getting to hot? That motor has an overheat sensor and a low oil level sensor in the tank as mentioned, first thing would be to see which wire is sending the signal to the alarm and isolate it from there.

Mine was beeping randomly too. I changed the impeller, ran it hard and noted it wasn't over heating. Knew there was plenty of oil, so I disconnected the beeper. Ran it hard and long and never had a problem.


If it isn't overheating, and there is oil in the tank, you should consider this. :wink: