1975, 70 hp Johnson impeller change

[Paddy60]

Good day.

I have the lower unit off and every thing looks good but will be changing out all the water pump parts I can. I did have some observations though. When I removed the pump housing and the base plate, there were no paper gaskets. When I ordered parts there were paper gaskets available so I ordered them i any case. Should I re-assemble with or with out the new gaskets? Just height issue.

Also, I noticed a fine film of mud on top of the lower unit/water pump area. Looking closely at the joint of the lower unit, at the front, there is a notch open the the water. So by looks of it, it's a flooded area. On top of the lower unit next to the water pump , there is a boot around the shift rod but does not look like it would be that that effective of keeping out water from making it down to the lower unit.

1) Is it OK to see a muddy film on top of the water pump/ lower unit?
2) Is the shift boot intended to keep water out?

Patrick T

 

[eavega]

Re: 1975, 70 hp Johnson impeller change

Good day.

I have the lower unit off and every thing looks good but will be changing out all the water pump parts I can. I did have some observations though. When I removed the pump housing and the base plate, there were no paper gaskets. When I ordered parts there were paper gaskets available so I ordered them i any case. Should I re-assemble with or with out the new gaskets? Just height issue.

I had a 76 Johnson 70 HP, and there were no gaskets between the pump housing and the base plate.

Also, I noticed a fine film of mud on top of the lower unit/water pump area. Looking closely at the joint of the lower unit, at the front, there is a notch open the the water. So by looks of it, it's a flooded area. On top of the lower unit next to the water pump , there is a boot around the shift rod but does not look like it would be that that effective of keeping out water from making it down to the lower unit.

1) Is it OK to see a muddy film on top of the water pump/ lower unit?
2) Is the shift boot intended to keep water out?

Patrick T

Don't know if I am much help here, but my understanding is that the entire area around the water pump is supposed to be wet, so a small film of mud would indicate nothing more to me other than running in silty water. While the shift shaft should be sealed (with the shift shaft seal) I don't believe the rubber boot is supposed to be water-tight.

Rgds

 

[classiccat]

Re: 1975, 70 hp Johnson impeller change

good questions Patrick. I'm about to button-up my LU from a reseal (waiting on parts) and wondered the same thing about the waterpump gasket.

How's this for sediment on my latest project


The boot did an OK job at keeping most of the crud away from the bushing.


this motor was a recent acquisition

 

[Paddy60]

Re: 1975, 70 hp Johnson impeller change

Bluefin,

looks like your motor sat in a slip with the motor down! After seeing yours, I'll be tilting mine up.

Patrick T

 

[classiccat]

Re: 1975, 70 hp Johnson impeller change

Bluefin,

looks like your motor sat in a slip with the motor down! After seeing yours, I'll be tilting mine up.

Patrick T

Nope, it was trailered. The PO was completely oblivious to the water pump's existence.

and the condition of this prop should tell the test of the story :lol:

 

[orbanp]

Re: 1975, 70 hp Johnson impeller change

Good day.

...
2) Is the shift boot intended to keep water out?

Patrick T

The shift boot keeps the water out of the lower unit, it is important that it is in good shape!

Peter

 

[classiccat]

Re: 1975, 70 hp Johnson impeller change

the o-ring inside of the shift-housing itself gives you your seal.

 

[Paddy60]

Re: 1975, 70 hp Johnson impeller change

So any word on the gaskets? All the parts just came in.

Patrick T

 

[xjdriver]

Re: 1975, 70 hp Johnson impeller change

On the bottom of your pump housing there should be a rubber gasket that fits into the groove. I think that was about it. I dont really see the need for another gasket below the wear plate, i dont think mine had one either.

 

[Paddy60]

Re: 1975, 70 hp Johnson impeller change

Anyone know the O-Ring size at the top of the drive shaft? I got the kit and I thought the O-ring that came with it was for the drive shaft upper. Must have been for somewhere below the pump.

Patrick T