How do you install the Mercrusier Alpha 1 Gen 2 lower unit, water pump coupling p/n 816597A1.

crackerjackcrackerjack Wasaga Beach, ONPosts: 11Member
Pulled the lower unit off for routine preventative mtce. Replaced the water pump impeller. NEED HELP with re-assembly.

The water pump coupling has a slot at the top edge, what is the slot for, what position should it be facing when installed. Above the pump coupling is a sleeve p/n 23-816583. How is the sleeve used to guide the water pump tube during installation. 

Answers

  • zaverin1zaverin1 Harrison TWP ,MIPosts: 1,522Member ✭✭✭
    Reassemble or rebuild the pump and leave the plastic sleeve in place.
    make sure oil passage o ring is in place and lift the sucker up into the upper.
    you will have to rotate the prop to align the splines with the upper.

  • Dream_InnDream_Inn Annapolis, MDPosts: 5,127Member, Moderator mod
    Also, when you lift the lower back on, make sure not to pump the shaft seal.  If you do, chances are it will leak (been there done that).  It's much easier with another set of hands if possible.  My first boat had the A1G2 drive and I learned a lot of lessons the hard way with that boat.

    Dream 'Inn III -- 2008 400 Express

  • zaverin1zaverin1 Harrison TWP ,MIPosts: 1,522Member ✭✭✭
    Look at google and you tube videos
    or post a pic here off the  assembled lower
  • crackerjackcrackerjack Wasaga Beach, ONPosts: 11Member
    Dream_Inn said:
    Also, when you lift the lower back on, make sure not to pump the shaft seal.  If you do, chances are it will leak (been there done that).  It's much easier with another set of hands if possible.  My first boat had the A1G2 drive and I learned a lot of lessons the hard way with that boat.
    Yes another set of hands did help. But I am still wondering what the slot in the seawater pump coupling does, put it in facing forward. Thanks 🚤 crackerjack 
  • crackerjackcrackerjack Wasaga Beach, ONPosts: 11Member
    zaverin1 said:
    Look at google and you tube videos
    or post a pic here off the  assembled lower
    YES “you tube” is generally pretty good, but every now and again I will be watching some how to type you tube video and wonder what is that guy thinking, he is so wrong or so unsafe.
    I have viewed many Alpha 1 Gen 2 lower unit install but have not found any body making any comment on the “slot” in the seawater pump coupling assembly. ??? Thanks 🚤 crackerjack 
  • zaverin1zaverin1 Harrison TWP ,MIPosts: 1,522Member ✭✭✭
    Post a pic
    i did a dozen water impellers on alpha 1
  • GMSLITHOGMSLITHO Greenwood Lake NY Posts: 575Member ✭✭✭
    If I remember right the upper and lower unit should be in Forward when you put them back together 
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