50hp 2003 Johnson - changing water pump

[lakelover]

I'm changing the water pump on my 2003 50hp. The 5/8" head bolt near the trim tab is stuck pretty good, I don't know if it has ever been removed. I don't see any visible corrosion & I've sprayed it with PB Blaster. I'm afraid to put my persuader on my ratchet handle for fear of breaking it.

Any suggestions or tips on getting it loose without wrecking it?

 

[lakelover]

Re: 50hp Johnson changing water pump

Re: 50hp Johnson changing water pump

Three cheers for PB Blaster, tapping and time. It's out without using the persuader. Although not sure how much good the PB did, as the threads are way up at the top of the bolt.

 

[oldcatamount]

Re: 50hp Johnson changing water pump

Re: 50hp Johnson changing water pump

Patients---the best tool in the box!

 

[lakelover]

Re: 50hp Johnson changing water pump - another question

Re: 50hp Johnson changing water pump - another question

The deed is done, but another question. Check out the water squirting out between the lower unit and the mid section in the picture below:

It did this before I removed the lower unit, and still does it now.

The question is, does it matter and do I need to do anything about it? I don't see that it's causing any harm. The telltale is squirting like a fire hose.

 

[James R]

Re: 50hp Johnson changing water pump - another question

Re: 50hp Johnson changing water pump - another question

Looks like the water tube is not engaged correctly or the tube seal is defective. Could be that you dont have a good seal on the pump housing.

 

[lakelover]

Re: 50hp Johnson changing water pump - another question

Re: 50hp Johnson changing water pump - another question

The water tube on this model consists of a tapered rubber grommet that fits into a tapered part of the bottom of the mid-section casting and just compresses when you tighten the lower unit. Seems practically impossible for it not to line up when everything slips into place. I thought maybe there was supposed to be a gasket between the mid section and lower unit housing, but there isn't.

The only thing I can figure is that the contact area is corroded in that area, you can see the pitting in the pictures. (This is the old pump):

New pump is well sealed with gasket sealer, to say nothing of how much I slopped all over the outside while sliding it down the shaft and aligning the key:

 

[James R]

Re: 50hp Johnson changing water pump - another question

Re: 50hp Johnson changing water pump - another question

Did you replace the two seals in the picture and clean the tapered seat in the casing. The only sealant I use is OMC thread and gasket sealer. Also use it on the bolts that secure the lower. That way it is easy to remove next time or suffer the consequences of corrosion especially if used in salt water. I seal all bolts on motors I work on.
Of course you may be over pressurising the system with the faucet pressure and the water has nowhere to go except passed the seal.

 

[lakelover]

Re: 50hp Johnson changing water pump - another question

Re: 50hp Johnson changing water pump - another question

Thanks, James. Yes to both questions. The motor has only been used in fresh water, but there was some corrosion in that area when I bought it. The PO said the water pump had never been serviced (6 yrs. old when I bought it). The lake it was used in has mildly acid water.

There is also a small cast hole in the housing in the front that water shoots out whenever it is running. Unless someone knows a reason to be concerned, I guess I won't worry about it.

I don't think I'm over pressurizing, it did the same thing in a barrel last fall.