How To Replace Mercury Outboard Water Pump Impeller

[MrCadbury2]

thank god I found your clip keep up the good work Im off to do my motor now

[Sierra2549]

Great video and excellent detail. I'm changing the impeller and thermostat on my 90hp 2004 merc this weekend. You wouldn't happen to have a video on changing a thermostat on on of these ;) ?

[BUCK83061]

do you have a vedio or anything to show how to replace reverse gear 75 hp merc buck

[arodriguezjtube]

Excellent video!

Thanks a lot!

[Unrelenting1]

Your my new best friend. Wow, that wasn't hard at all. Thank You for that!

[oberfour1]

Thank you very much!

[sparrfarm]

This is the best how to install a water pump. Getting the lower unit out and putting to lower unit back. I learned why the impeller is bad and the hardest part for me is to put the lower unit back. This video is the only video that anyone would need to know how to install a water pump. Thank You for your help!!!!

[tasmania105]

I just replaced the water pump on my outboard but now whenever when I'm on the water and I put it in gear it goes in the wrong direction. For example, if I put it in forward it goes backward and if I put it in reverse it goes forward. Do you know how I can fix this?

[bencooke29]

@tasmania105 I had the same problem. the drive system is spring loaded and it went into forward drive when you took out the shaft because the gears are spring loaded. I haven't had time to figure it out yet but some how you need to take the lower end off again and try and figure how to put it in nutrel be for putting the shaft back in. It may take two poeple to do that so one person can hold it in nutrel while you put the shaft back up into place

[classicoutboards]

great video however instead of grease on the bolts, I use evinrude gasket sealer on them.

[healthyliving100]

Hi, to remove and install the gearbox best to be in neutral. Its a little tricky to install those impellers as the water pump housing is on the gearbox. So you need to be turning the driveshaft as yo install in the impeller. Turn driveshaft clockwise.

What to look out for - make sure all the blades of the impeller are going the same way.

And make sure the key for the impeller doesnt fall out when installing impeller.

[petewv]

I have a 1965 9.8 mercury outboard 11O . ser # 1875542. I would like to change the impeller. What are the steps and what should I look out for in the impeller installion?. My first question is what gear should the motor be in? how hard is to install a impeller?

[chabuy]

Hello OutboardAdvice, I need replace my lower unid, I have a long shaft lower unit but a friend have a short shaft, can I switch the shafts when replacing the water impeler without taking the gears out just pulling the shaft out?

[petieohalloran]

hows things

how hot should the water be comin out of tell tale hole.

is the drive shaft housing supposed to be hot. thnx mate please let me know asap

peter,,,ireland

[OutboardAdvice]

@petieohalloran Hey Peter.

The tell tale water should be around 40 degrees celcius. It comes off the exhaust plate so this should stay cool.

The driveshaft should not get hot, it will get warm,, but not hot.

Hope this helps

[OutboardAdvice]

@petieohalloran Two water oulets just above prop... Is your motor a v6? Or the same as in the video?

[petieohalloran]

@OutboardAdvice hey mate ,sorry for gettin back so late ..yes my engine is a v6 150 year 1999

[OutboardAdvice]

@petieohalloran It is normal for a V6 to that! The water pump tell tale wont flow untill a v6 is up to temperature. They operate at around 60 degrees C or 143 degreis F, so this will be very hot to touch.

You will also notice it takes a while to come out of the tell tale. As long as when you start it up, the two holes above the propeller start pumping straight away you should be ok.

I recommened once a year or at 100 hours replacing the water pump, checcking thermostats and the pressure valve

[petieohalloran]

@OutboardAdvice thnx mate for that information, you are the only one who could give me results on the problem.your a wizard

[OutboardAdvice]

@petieohalloran Cheers, Your welcome :)



[petieohalloran]

@OutboardAdvice by the way wats the pressure valve and where is it ....thnx wats your name.

[OutboardAdvice]

@petieohalloran The pressure relief valve is a valve that 'pops' off it seat when the engine rpm is increased which increases the water pressure. It bypasses the thermostats etc and make the motor run cool at higher rpm. It has a rubber grommet that gets squeezed in by salt build up and pinches on the plastic valve. There is also a diaphragm that needs servicing/replacing if it is stretched, perrishing or gets a hole in it.

[OutboardAdvice]

@petieohalloran

The valve is located on the starboard side of the motor, under the electrical panel. You will need to remove the trays ( lower engine covers) to access it.

names Geoff :)

[hlub82]

Thank You. very well done. Hats off to you my friend.

[radoslavrigas]

Hello,

I noticed when you removed the lower unit, the black water tube was not attached to the water pump. However when you are reinstalling the lower unit, the water tube is there. Is it part of the kit? Was yours still in the driveshaft housing which is why we didnt see it coming out?

[OutboardAdvice]

@radoslavrigas

Hi, yes some kits come with the black tube. Depends what kit you get. When you remove the gearbox the tube can stick onto the water tube. You simply reach up and pull it out then fit it into the water pump.

It is there as a guide for when you install the gearbox to get the water tube to slide into the water pump housing.

[jshell3]

Excellent!!!

[michaelb7280]

extremely thorough...even for those with add !

thank you

[OutboardAdvice]

@michaelb7280 Thanks for the comment :-)

[ober51]

Great video, really helpful. Will it be similar for my 1997 60 HP Mariner? I am attempting to do this for the first time on Saturday. Any advice is appreciated.

[OutboardAdvice]

@ober51 Thanks for the feedback!

You will probably find it is exactly the same water pump. If it has the quickfoot gearbox I think. So if you follow the video you should be great! The only thing I have noticed from comments is the gearshift. Before putting the gearbox back onto the motor, rotate the prop shaft and confirm that it is still in neutral and you havent accidentally turned the shift shaft. Good luck!

[ober51]

@OutboardAdvice Awesome, thanks again. I've never done this before, so I will report back.

[angieaew]

All sorted out and roaring around the bay like there is no tomorrow. Many thanks.

[angieaew]

Hi, I have just replaced the impeller as per your video but I do not have any reverse gear. The impeller works fine as water is coming out great. What have I done wrong. I have made sure that the gear shift has engaged correctly but do not know what else I can do. Any suggestions would be greatly appreciated.

[OutboardAdvice]

@angieaew Hey, Did you get the gear shift sorted out?

[zgetz444]

Awesome job with explaining how to do this job, it almost looks easy.

[rchenderson2000]

Great video. thanks for posting. Just what I need to rebuild the water pump. thanks again!!!!!

[SuperBasszilla]

is there any difference with an merc optimax 115? 

[ggmohl]

What keeps that rubber washer down on the housing? Seems like once housing fills with water it will push that right up the shaft.

[wil2294]

Great stuff ;-)

[OutboardAdvice]

@wil2294 Thanks, glad you enjoyed it.

[Dualcats2]

I have a Johnson 120 HP, is it about the same to replace the water pump?

[OutboardAdvice]

@Dualcats2

Similar... You will need to undo the gearshift rod under the carburettors before you can take the gearbox off your motor. It will be a 1/4 inch bolt that you will need a 3/8 inch socket to undo.

[OutboardAdvice]

Did you use the gaskets? The plastic tube is just a guide to guide the water tube into the housing, so thats ok

That kit also does mercruiser alpha 1 water pumps so that is why you had extra bits.

Depending on how deep the grove was in the housing... I very small grove is pretty normal. I would get a housing for next time you do the water pump. It is caused by sand and grit etc getting sucked into the water pump and is very abbrasive....

[alib33]

Yes, I used the gasket and everything you mentioned and started the motor and it pisses water well.

It just bothers me that I may have put the "water guide seal" or "water guide tube" upside down.

[alib33]

I'm done. none of the "O" rings or other accessories from the kit were used. Just the key, impeller and the top seal rubber washer. Also, not sure which way the short plastic cylinder rests on the opening of the housing (black plastic short cylinder with two different size ends)

Started the motor and it pumps water a lot faster than before. Also the inside of the housing had a very very small groove but I hope that fine please advise if i need to worry about any of the above. Thanks again,

[alib33]

Just a couple of questions before i roll up my sleeves and get busy,

1. Do i have to worry about this Shift linkage that was mentioned too

2. Do I need to drain the lower unit oil prior to doing this

3. What type of silicone did you use to seal the exhaust....!?

I didn't exactly understand that sealing part

Thank again.

[OutboardAdvice]

@alib33

Just make sure it is in neutral when you remove the gearbox, and dont turn the shift linkage when you have the gearbox off.

No you don't need to drain the lower unit gear oil.

A high temp silicone is preferable. But any gasket sealing silicone will do.

The silicone seals the exhaust gases from going back into the water pump area.

[alib33]

You ROCK.

Thank you for posting this.

I have a 2003 mercury 90 hp. Is this pretty similar?

Thanks again

[OutboardAdvice]

@alib33

Exactly the same.... Thanks for the comment

[artlawton]

This is a great video.  Thank you very much for posting it!......

[OutboardAdvice]

No you don't. You only have to drain the oil to replace it. That should be changed once a year or 100 hours, which ever comes first.

[OutboardAdvice]

No you don't. You only have to drain the oil to replace it. That should be changed once a year or 100 hours, which ever comes first.

[InTehMountainz]

do you have to drain the lower gear box before removing?

[fishman677]

Thanks for taking the time to make your video! I own a 1987 Mercury Mariner 75HP and have hesitated to replace the water pump myself. Thanks to you I will be doing it in a few weeks. You took the mystery out if it and made it clear and simple to understand. Keep on making videos! Thank you.

[cageboyes]

It's good when people in the know share there experience. I want one of these for an older Blue Band Mercury 115hp

[OutboardAdvice]

Thanks everyone for the great feedback and comments, really appreciate it. This was my first tutorial video so its a bit budget.

I do plan to do more maintenance videosbut have been busy with work. If you do want to get notified about new videos you can subscribe to me.

[calumnicol]

great attention to detail, really helped me understand what exactly to do. thanks

[webturbo]

What a great tutorial. I've watched several on here and this one is by far the best presentation .. I like the fact that you didn't get overly technical, but kept it easy for the everyday "shade tree mechanic" to understand.

I will be changing the impeller on my 75hp Merc in about 2 weeks and will have my laptop on the workbench for reference with this video cued up!!

Thanks again!

[OutboardAdvice]

What year 50 is it? Most mercs are on a spline with the shift so it will come straight off. How hard did you pull the gearbox where it sticks? Some get a little tight when the engine mounts etc get a bit worn and sloppy.

[LU8HRW]

Nice and clear video.Good work!

[jasoncady]

@OutboardAdvice

I am in the process of doing a Mercury 50 and on my motor there is a nut that you have to loosen on the shift linkage. It is on the front side of the lower unit and is accessible prior to loosening the other 5 bolts holding it in place. I had the same problem as another person here where it only dropped down about and inch or too unit I disconnected the shift linkage. Hope this helps someone else with a similar motor in the future. Great video by the way.

[OutboardAdvice]

@jasoncady

Thanks for pointing that out - One piece of advice to anyone with this style of motor. Undo the lock nut first, just enough to nut hold the joining nut. Then undo the joining nut to remove the gearbox. Don't move the locking nut from here. When you install the gearbox, do the joining nut back up then nip up the lock nut. This should keep the shift rod in the same position as before. If you put it back in a different position, the gear shift linkages can be out of adjustment.

[OutboardAdvice]

@jasoncady

Thanks for pointing that out - One piece of advice to anyone with this style of motor. Undo the lock nut first, just enough so it's not holding the joining nut. Then undo the joining nut to remove the gearbox. Don't move the locking nut from here. When you install the gearbox, do the joining nut back up then nip up the lock nut. This should keep the shift rod in the same position as before. If you put it back in a different position, the gear shift linkages can be out of adjustment.

[1freedomfighter11]

I am trying to do a 50 HP Merc and it wont come off, it comes down about an inch and sticks, am i missing somthing? I am woundering sif i am missing a linkage for the gears or somthing? Thanks for the video.

[Broadside175]

Well done!, I'll be doing that to my 125 this week. Kudos for going the extra mile and greasing everything for the next time!

[1967fishdude]

thanks 4 the effort mate good video

[maxpower7581]

What kind of boat is that?

[OutboardAdvice]

It is a Fi Glass Firestar Bout 17ft

[Flappyization]

very well done mate. just finished on my mercury 75 brown band. cheers

[keithblade]

Thank you, very well presented, having my first go tomorrow.

[OutboardAdvice]

@keithblade Good luck! Let me know if you have any questions... Most important is making sure you get the water tube in and the gear shift shaft lined up when putting the gearbox back on...

[xdalth]

Awesome dude! nice and clear info. Nice work

[Johnnyd352]

Nice video, great advice. Have been wanting to do my waterpump for ages. Nice simple step by step. Cheers