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  1. #1
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    Apr 2020
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    Casper, Wyoming
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    2005 Optimax 115 Continuous Alarm At 4000 RPM

    05 Optimax 115, Serial 1B118216

    Boat starts and runs fine until I hit 4000RPM, then I get a continuous alarm. If I back off below 4000 the alarm turns off. Seems to be more of an issue in the mornings and happens less as the day progresses.

    Oil is about 2/3 full in the reservoir and seems to be be using oil at the regular rate. Oil cap is tight.

    Only thing I've changed since the alarm started going off is the impeller. Boat runs great at about 27 mph until I hit 4000 and have had it out for several day trips in this state. Can't get in to see a mechanic for months so any help is greatly appreciated.

    Thanks in advance!

  2. Member
    Join Date
    May 2011
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    Spangle, WA
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    6,180
    #2
    A continuous solid tone or continuous beep? Without a Smartcraft device your best course of action would be to have a Mercury dealer do as suggested in this topic - WARNING HORN "BEEPED"
    _______

    Phil
    '09 Hewescraft ProV
    '09 150 Optimax


  3. Member
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    Apr 2020
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    Casper, Wyoming
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    #3
    It is a steady, unbroken tone until I back off below 4000 rpm.

    I don't have smartcraft, but like I said every marine mechanic for 100 miles is booked through July even for a scan, which is why I was seeking advice from the community so I can get back on the water.

  4. Member
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    May 2011
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    Spangle, WA
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    #4
    The solid tone is a CRITICAL alarm condition. With no data to work with it could be anything. Blind recommendation, if water pump has not been serviced in the last 365 days, do that first. If alarm condition remains afterward you'll need to make an appointment.

    I highly recommend you consider adding a Smartcraft device of some kind - SMARTCRAFT Options
    _______

    Phil
    '09 Hewescraft ProV
    '09 150 Optimax


  5. Member
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    Apr 2020
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    Casper, Wyoming
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    #5
    For anyone reading this...the alarm at 4000 rpms was caused by a shift position switch under the oil reservoir.

  6. Member
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    Nov 2010
    Location
    Ontario, Canada
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    #6
    The dipstick mounted under the oil tank fill cap can come off and fall to the bottom of the tank, fooling or jamming the senser to send a low oil warning. On my 2012 75 Optimax (same engine family as the 90, 115 engine), my tank was replaced under warranty because of this, I removed the dip stick and now just remove the cowl to check oil level, usually only have to refill 1-2 times a year. Try to keep the reservior between 1/3 -2/3 full. There is a You-tube video on this problem.

  7. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
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    Apr 2008
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    Greenville, SC (US)
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    #7
    Quote Originally Posted by metallife89 View Post
    For anyone reading this...the alarm at 4000 rpms was caused by a shift position switch under the oil reservoir.
    Thanks for updating with an outcome on it.


    Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
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