Merc 60HP Water Pump

[LMITOUT]

I think it may be time to change out the water pump/impeller on my 60HP Mercury. Anyone have experience doing this? What are the steps that need to be done? Anything to be watching for when disassembling and reassembling? I bought the impeller and gasket a while back figuring I'd have to do this someday and I think someday is here.

Thanks!

[Benny]

If it is a 90's 60 it is just like my 40 hp.

Best thing to do is go to the library and check out a maintance manual.

Then follow that to get er done.

But the water pumps are easy on the mercs.

First mark the little aluminum fin on the bottom of the lower unit where it sits.

Drain lower unit oil.

Then put the shifter in Foward.

Take note where the prop postion is as well.

Remove the little black plastic pop in cover on the top of the lower unit fin.

Loosen the two side nuts, remove the bolt from inside the lower unit fin found under that plastic cap.

Remove the nut from under the bottom of the lower unit fin, you have to get down and look to see it from the ground up.

Remove the little aluminum fin.

Then slowly remove the two side nuts and gently pull or tap the lower unit off.

The shaft will come out as one piece sop you will need to tilt the motor up or have clearance under the motor.

After you get it off, the water pump is right on the top with the long shaft going through the housing.

There are three nuts holding it on to the lower unit, also watch for the rubber snubber and the exhaust rubber.

They may fall out or stay in the upper unit part.

After you remove the three nuts just remove the housing and replace the impeller, or the whole housing as it will come as a kit for around $80. any way.

Make sure you get the gaskets and metal dividers in right or you will plug the water ports.

They are pretty straight foward and hard to get backwards though.

Grease up the shaft splines and the tip of the shaft.

Then just slip the shaft back up into the upper unit being careful to not force any thing.

As the shaft inters the gear housing , you will have to work the fly wheel back and forth a little to get it to mesh in, but do not turn the fly wheel more than a 1/8 inch either way.

And again do not force any thing, it should slid right back in if it aligned up right.

You can blow out the case if you force it in.

It may take a few trys to get it to fit nice.

Then start the two side nuts on and work the unit back up on to the upper unit housing.

You will also need to hold the water tube up in place and fish the air breather line through the case as well.

The water tube will go in as you lift the lower unit up into place. the air line should go through it's hole and out the back side.

Never rotate the impeller back and forth, it only goes one way.

Look at the old one to see how the fins are curved, this is how your new one wil look.

The directions with the water pump kit will explaint the direction of rotation.

There you should be done.

Benny

[Valv]

Wow Benny, you are awesome, this was a great description of the job.

I have to add to be careful not to torque water pump housing too much or it will break the plastic, it has to be tight but excessively.

This instruction works with most outboards except Evinrude / Johnson, but it's very similar

[LMITOUT]

Benny, thanks so much! I've never been inside a boat motor/lower unit before so your instructions are much appreciated. I figured there wouldn't be much to the tear down, but it's the little things that make the job go easier.

I didn't buy the housing so I'll have to inspect it when I have everything apart to see if it needs to be changed also. I didn't see any direction indication on the impeller and it appears to be straight with no curved fins. I've seen used impellers and they are curved when they come out though. I'll take a closer look to make sure.

I have a '99 Merc, BTW.

Thanks again!

[Valv]

The new impeller has straight fins, the used will be bent, it's a little bit of work to insert new one inside pump, BE VERY careful about the small shaft key, it can fall off easily, usually I use a little dab of silicone grease or regular grease to "stick it" to shaft.

Also underneath rear fin there's a hidden bolt, you'll see it looking up from where fin was. Remember unit has to drop by itself, or maybe just a wobble/wiggle. If you have to use a prybar or scredriver....STOP, you missed some bolts, check them all again.

Once you dod this a couple of times it will be very easy, I do it every year before open water.

[LMITOUT]

Thanks Valv. One more question....is there any sort of gasket or seal between the lower unit and motor that needs to be replaced?

[Surface Tension]

Nice post Benny.

No seal between the halves.

[LMITOUT]

Thanks Frank!

[Big Laker]

LMITOUT,

If your 60hp is a bigfoot model you may have issues. I replaced the waterpump on my 60hp bigfoot and the waterpump kit is slightly different if its a bigfoot.

[LMITOUT]

It's not a Bigfoot. Thanks for the heads up though.

[LMITOUT]

Got the new pump in! Took me about an hour including draining and refilling the gearcase which I didn't feel was too bad considering it was the first time I've done it. It wouldn't drop off very easily and it seemed to be sticking in the front. A slight pry with a screwdriver and it popped right down. The old impeller was getting hard and the housing looked perfect. Took it up to the lake in town and backed it in far enough to run. It's been a while since I've had a stream like that come out. Good to go now!

Thanks everyone!

[Benny]

Glad it went smooth, now your the guy the neighbors will go to to have thiers done.

I placed that post just by memory, but I had to replace mine twice and had to replace the prop shaft once already too.

Now that gets a little technical when you dig into the gears.

But it still wasn't to bad if you have enough beer and a large garage floor to lay everything out as you pull it apart.

Benny

[Valv]

Wow, 1 hour ? That's great, it's about what takes me to do it and I've done it many times.

Now that you saw it's not very tough you can see why it's a good practice replacing it every year or 2, cost is minimal and benefits are HUGE.

Benny thank you a lot for your excellent description.

[LMITOUT]

I had good instructions.