Replacing water tube part that's obsolete on 1983 Johnson 7.5hp

[redfishsc]

Have been having issues with my water pump, so I thought, but it turned out to be a bunched-up rubber retainer that sits at the top of the copper tube where it mates up to the engine block. I will try to call Seaway soon.

It's part #69 on the 1983 J8RCTA models (I can't link out to them from here, it gets edited out).



I have a parts-only motor (1986 6hp) that is a near clone to this one, but this one had a rotted retainer as well, so I'm dead in the water.

This particular motor (1983), however, has a flared pipe and the retainer adds no rigidity at all to it. I really cannot see what function the retainer serves, it seems like the gasket itself will provide all the seal necessary. On my 1986 parts motor, that retainer does have an obvious function but it's different than the 1983 I'm actually trying to repair.

Has anyone pulled one of these apart before? Is it possible to reassemble and use this without the retainer? Is it possible to use something like perhaps a fat rubber o-ring?

 

[schematic]

Re: Replacing water tube part that's obsolete on 1983 Johnson 7.5hp

BRP-0324604 still an available part

 

[redfishsc]

Re: Replacing water tube part that's obsolete on 1983 Johnson 7.5hp

Schematic, thanks. You are right. However, the pics I've seen of this show a U-shaped rubber retainer, but the one that was on this motor and on the 6hp version that I tried to rob were both round and looked somewhat similar to the rubber grommet between the pump housing and the copper tube (not identical but similar).

I am going to go back to the motor here in a little while and see if I can figure out how the U shaped part will work, I guess my only option is to order it and see if it fits.

 

[itsaboattime]

Re: Replacing water tube part that's obsolete on 1983 Johnson 7.5hp

I have in the past used fat rubber "O" rings to seal the water tubes. It can be tricky though. You have to make sure that the "O" ring creates a perfect seal. The worst part about this kind of jury rig is that you don't know if the seal is perfect until it's all assembled and running. If it doesn't work you have to pull it all back apart and start over.

 

[redfishsc]

Re: Replacing water tube part that's obsolete on 1983 Johnson 7.5hp

I have in the past used fat rubber "O" rings to seal the water tubes. It can be tricky though. You have to make sure that the "O" ring creates a perfect seal. The worst part about this kind of jury rig is that you don't know if the seal is perfect until it's all assembled and running. If it doesn't work you have to pull it all back apart and start over.

I much appreciate your help! Glad to know that a fat O-ring can work. I usually don't take my outboard so far out that I can't motor back safely on the trolling motor so I have a little leeway in playing around with it.

I need to take a pic of the underside of my engine block because I am getting conflicting information and I want to at least attempt to do the right thing.


The original retainer was a rubber grommet/O-ring. It's swollen and plugged. However, the retainer sold by other places (and occasionally listed for the 4.5hp only) shows a U-shape retainer (same rubber, different shape).

The underside of the engine block does not have a simple round hole. It is a groove about 3/8" wide. The water tube mates up with one side of that groove, and the actual hole where the water goes up into the block is off to the side a few inches recessed up into the block. In other words, the round inlet on the engine block is offset from the location of the water tube.


I am going to order the U-shape retainer today and give it a shot. If it works in the barrel, I'll charge up my battery (just in case!) and take the motor out for a long, hard run to make sure it isn't malfunctioning.