# Water pump change on a Mercury 150 Black Max ????



## z71mathewsman (Apr 9, 2012)

Anyone on here ever changed one? I got a 1995 Black Max XRI,that had the alarm go off on me at the lake this past Friday,just curious how hard they are to change?Watched a few vids on youtube,seems pretty simple.


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## BoosterC (Apr 9, 2012)

As a first time changer, it would be best with 2 people.  The lower unit can be heavy and awkward by yourself.
1st key is put the motor in gear before dropping the lower unit.  This will be crucial in getting it back together correctly.

2nd is there is a bolt under the trim tab(zinc sacrificial anode).  This drove me nutz the first time, and I had a service manual to look at when I changed it.

3rd is make sure the water tube is aligned properly when you put it back together.

Depending on when it was last changed, you may only need to replace the impeller and the o-rings rather than the entire pump.  This will save you a few dollars,  but be sure to inspect the pump housing for any cracks.

When your alarm went off, was your motor peeing water as usual?  Dirt daubers are notorious for getting in and plugging the pee hole as they build a nest.

Last, have some ibuprofen ready for your forearms after you wrestle the lower unit back in and get it bolted   This will help your lower back, as well.   Good luck!


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## gahunter12 (Apr 9, 2012)

I replace mine on every outboard I have ever owned. It's very simple.
 1) Make sure you have it out of gear
 2) remove all the nuts and one bolt toward the back. You 
      may have to remove the torque tab. 
 3) Carefully lower the lower unit until the shaft clears the 
      leg ( mid section). There may be a rubber tube that 
      needs to be removed for the speedo. 
 4) Remove the bolts from the impeller housing. Should be
      three bolts. 
 5) Slide the housing off the shaft.
 6) The impeller may come off with the housing. If not just 
      slide it off while being careful not to lose the key if it 
      Comes off. 
 8) Clean and inspect the housing and impeller base plate 
      which will still be on the lower unit. 
 9) if you see any gaulding or damage on the inside of the  
      housing or base plate, replace it. Also check for cracks 
      in the housing. 
10) Slide the new impeller on the shaft. 
11) Then lube the inner race of the housing and slide it 
       over the shaft. You may have to twist the housing 
       counter clockwise to get it to slide over the impeller. 
12) Install the three bolts in the housing.
13) carefully slide the lower unit back up in the leg guiding 
       the shaft in to the hole leading to the crank shaft. 
14) Make sure you reconnect the speedo tube if need be, 
       then if you are lucky it will slide up in place. You may 
      Have to help guide the tube down over the impeller 
      Housing. If the lower unit doesn't slide in place, have 
      some one to pull the kill switch and bump the starter 
      while you push the LU up. It will slide right in place. 

15) Bolt her up and you are done! Takes me about 30min 
       to replace mine.

ONE MORE THING! DON'T TWIST THE GEAR SHAFT WHILE THE
LOWER UNIT IS OUT! You will be making a trip to the dealer. The small gear changing shaft will be hanging down from the leg make sure you line it back up when reinstalling the Lower unit.


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## Fishin & Hunting (Apr 9, 2012)

U tube is your friend on this also.


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## retiredkilla (Apr 10, 2012)

make sure the new impeller is twisted in the new housing the correct way.[  gahunters #11  ]. good luck..


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