Alarm Going Off
 

Hello fellow Mariah Owners. I have a 2000 Mariah Shabah Z250 Limited Edition that we took out this past weekend. Went cruising for about 30 minutes before we anchored and turned off the boat. Everything was running fine. A couple hours later we set out for another cruise and when the boat turned on an alarm buzzer sounded. I checked my fuel level which was fine. My battery was fine at 14 volts. My oil pressure was ok and the engine temp was about 175 degrees. I went cruising and after about a minute the alarm went off. Than about 15 minutes later it went off again. Everything seemed to be running fine. Again, the engine seemed fine but I don't want to keep running it if there could be a serious problem. I would like to try and resolve myself if possible.

Does anyone have any idea what could be wrong with it or what to check?

Thank you for your help.

Alarm Going Off
 

Have you tried checking the oil and drive lube levels. If either one is low, an alarm will sound

Re: Alarm Going Off
 

This question gets asked quite often. The alarm monitors 3 things. Oil Pressure, Engine Temperature, and Gear Oil Level. Check your drive oil reservoir before you go (it's the clear plastic container located on the top of your engine block. Make sure it's got enough fluid in there. Then keep your eye on the oil pressure and temp gauges. Watch for any abnormally high readings (oil should be around 40 and temp should be around 180 i believe). If the engine temp is too high then you likely have a blockage in your cooling system. When was the last time you had the water impeller changed?

Sounds like its a good time to invest in a Mercruiser manual. They are available here on our site to our contributing members. Here is a link on how to make that happen.

Re: Alarm Going Off
 

Aaahhhh..the annoying intermittent alarm. If your gauges are reading a pretty consistent level, then I would exclude a gauge. Is your temp gauge operating correctly? Maybe it is a plugged port on your out drive and it's not getting enough water in. The reason I say that is because I blew a 454 engine that way!(yes, I learn the hard way!!)

Re: Alarm Going Off
 

On my Z250, the drive lube reservoir sensor went out, which caused the alarm to activate. Even though the reservoir was full with good drive oil, the sensor went bad which necessitated replacing the whole reservoir (the sensor is integrated into the bottom of it). If I remember right, the reservoir was pretty cheap. <$75.

Re: Alarm Going Off
 

Based on your description of the problem it is most likely the drive oil level. When the drive oil is cold it shrinks in volume and the alarm can go off. Once you start running, the drive oil heats up which expands its volume and sensor will turn off the alarm. Try adding just a little more gear lube to the drive oil reservoir so the float on the sensor is floating at the top of pin it rides on...when the drive oil is cold.

Re: Alarm Going Off
 

I will echo the drive oil level diagnosis. I had the same problem, added some quicksilver, problem solved. Hope that's all it is for you.