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My 1991 75hp outboard has a constant beep alarm. what is it and what can i do ? Mercury brand

Posted by Larry Ross on


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  • 1 Answer

SOURCE: 4 beep alarm - Mercury 150 efi outboard

when the engine is running there is a repeated 4 beep alarm every 5 to 10 min. i have talked to several repair shops and they are unsure of the problem. what is the proper solution to fixing this alarm?

Posted on Apr 29, 2010


Phil Walker

  • 608 Answers

SOURCE: I have a Mercury 90

Hi, follow the wires from the bottom of the oil reservoir and unplug them at the connection. If the alarm stops then the sensor or built in float is faulty. Replace the sensor first, if this solves the problem no more action is required. If it still alarms you will need to replace the reservoir as well, as the float is not removable. Hope this helps, regards Phil.

Posted on Jul 07, 2011


Colin Stickland

  • 22485 Answers

SOURCE: mercury outboard 3.5 motor stalls

not sure here as i normally answer car questions but if this engine is of the new generation and its all electronic then it has to be plugged in to locate the fault .My outboard was playing up like this with loss of power and the dealer wanted a small fortune to repair the pump which feed the fuel injection system so i took it apart and made a new valve for it out of a piece of fishing hook plastic wrapper and a bit of copper wire hook type thing i made and that was about 5 yrs ago and its still running fine

Posted on Apr 13, 2012


johnny bonacci

  • 258 Answers

SOURCE: What might cause the warning system on mercury 50hp outboard to beep 3 times every 4 minute s

That is the engine default code. It has to do with the regulator not getting enough water to cool it down. Those are water cooled regulators not air cooled like cars. The impellers for the cooling system should be replaced about every 3-4 years. It may still cool the motor but not enough to cool the regulator which supplies the computer to set the trouble codes.

Posted on Jul 21, 2018

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