Reply To: Merc 300 The Boss’s Motor

Home › Forum › Ask A Member › Merc 300 The Boss’s Motor › Reply To: Merc 300 The Boss’s Motor

June 7, 2023 at 2:35 pm #276818
fastjohn
Participant

    US MEMBER PAY BY CHECK

    The holes in the flywheel should be 5/16 – 24.  The small screw below the cavitation plate is for the vent.  Mercury specified  grease in all lower units through 1959.   Since there were no significant changes in 1960, grease should be fine in your lower unit.  John Deere corn head grease is preferred  by most Merc guys today.