In this video on our annual service of a 40 hp mercury Four stroke outboard motor I go through all the steps involved in replacing the water pump impeller. Including removing the Lower unit, inspecting and replacing the impeller. I also give a demonstration and description of how an outboard motor water pump actually pumps water. I show you how to install the lower unit and how to identify what gear the lower unit is in. I show you how to get the splines to line up so the lower unit is easier to install. They can be very difficult sometimes.
0:00 How to remove the propeller and Lower Unit
5:45 How to Inspect & Replace the Water Pump Impeller
10:07 Description of Water Pump Operation
17:02 Installing the New Impeller
27:16 Description of the Shift Shaft Operation
29:00 How to Install the Lower Unit.
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Just ran across this, this is a great and informative video
Nice tips and great explanation of all. Thank you
best video on this i’ve found, thank you sir!
The Sierra 18-3324 Water Pump Kit below is recommended for your outboard 40 hp Mercury 2 stroke. The kit model #WATER PUMP KIT 77177A3 your Mercury 40 hp is a little different than mine as I only have two bolts that hold the bottom end on. Does that make mine older or newer than the one your working on?
Gday mate you do a good thorough job id be happy to let you work on my engine ,i have to say that leg and even inside the propellor looked a bit nasty is it corrosion or calcium build up either way didnt look good , never to much grease except on the top of the shaft especially in salt water ,we dont get much sierra gear here i think you can get it but you have to find a retailer and frieght from the U.S to A.U is a killer wanted to but some spare mounting bolts for my yamaha frieght was around 60 dollars for 4 bolts anyway good video .
My dads been using the same one for 20 years before it went.
Thanks for this great video and i tested my 90 HP Mercury and my pump is out. I am use to working on my car, my LT1 trans am. So now I know how to handle the water pump.
Did mine went back together perfect, thanks so much!!!!
Very nice video! Very instructional and the reference to why not to use impact wrenches on sensitive or bolts which may be corroded. Thanks!
Why not just put everything in forward before you take the lower unit off?
Glad I came across your video – nicely done! I have seen a couple other videos on the subject impeller replacement, however, yours is by far the absolute best. Simple but sufficient detail. I will use it to guide me through the process on my new to me 2018 40 hp 4 stroke motor. Thank you sir!
This is probably the best instructional video I have ever seen. Thank you for sharing your knowledge!
Hi, I have a 2012 Mercury 60 hp, My question is, does the low pressure fuel filter be full of fuel all the time? I notice that it is almost empty while running.
Tell me about the bent vise
I will never complain about what it costs to do this maintenance again.
Would you happen to know if it’s safe to use Lucas multi purpose Maine grease for this? It’s the grease I use in my wheel bearings.
Will this be the same on a 2012 mercury 40hp 4stroke?
Great video thank you! Your Volvo Penta videos seem to get the most views. I sent you a message on the website, I’d be happy to bring my boat with twin VP 4.3gxi sx drive engines for full service with you, even if you are about 5 hours from my home port. You can use it for filming more VP content:)