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  1. #1
    Join Date
    Dec 2005
    , alabama, usa

    Default "first question is about my ta

    "first question is about my tachometer. how do i fix it or check if prob is coming from engine. my boat is a 1986 bumble bee. i got a 1979 mercury 150 on it now...this is not the original engine of course but the tach has not worked since ive owned it. i think that another brand engine (unknown kind) came on boat so the tach. on the dash is whats hooked up to my merc. well the tach. sometimes bounces up and down like a broke speedometer in a car and sometimes it dont do anything. someone once told me to check the rectefier to see if its putting out right but how do i do that? second if it is putting out right, do i need to get a tach that compatible with a merc or is that how it works with marine engines."

  2. #2
    Join Date
    May 2006
    Nampa, Idaho, USA

    Default "Does your boat have a voltmet

    "Does your boat have a voltmeter on the console? If it does, what does it read at anything above 2000 RPM (or cruising speed since your tach doesn't work). If it shows anything above 13 volts the rectifier is working. Less than that you have a charging problem. Since the tach gets its signal from the rectifier, if its bad you get no tach reading. BUT -- since the tach bounces periodically, loose connections come to mind."

  3. #3
    Chris1956's Avatar
    Chris1956 Guest

    Default "Jimmy, That tach needs +1

    "Jimmy, That tach needs +12VDC, ground and the stator's pulse to operate properly. On your motor, these should be located in the Mercontrol box, front molded plug. Usually the tach itself is set to a 12 pulse setting.
    It is a good idea to check the rectifier as well. Easiest way is to start the motor and measure for DC and AC voltage at the battery. If you read AC voltage, the rectifier is bad. If you read 12 VDC or less the rectifier is bad. The DC voltage should rise as you increase the motor speed to high idle."

  4. #4
    Join Date
    Aug 2007
    Morgan Hill, California, USA

    Default "My father needs a new tachome

    "My father needs a new tachometer for his boat but is not sure which model is appropriate. He has a 115hp Mariner engine from 1991. I am helping hm find a tachometer online. We are looking for the Medallion models but cannot find them so have been checking out Teleflex instead. Any advice you could give would be appreciated. Thanks, Robin."

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