Replacing 1990 Johnson 200 Water Tube

[rapishorrid]

I pulled the lower unit off my motor and found that I need to replace the copper water tube that connects to the water pump.

How hard is this job? Do I need to pull the power head? Remove the midsection? Or can I do it with just the lower off?

 

[sutor623]

You will need to pull the powerhead and the midsection apart to get the water tube out. It is quite the job. Honestly, if I were you I'd pull the lower, measure the tube, and get a copper tubing cutter and cut off the damaged section, then some plumbing solder and attach a larger piece of copper around the existing tube, then then slide the new piece of copper into that and solder it all up.

If you are leaking water from where the grommet is at the top of the water tube then you will need to remove it properly to change it.

 

[rapishorrid]

The tube actually broke off about 8" up from the water pump (right where it begins to curve). I like the idea of soldering on an extension, but I'm not sure I'll be able to get tools in there high enough to make it happen. Pretty sure the pipe broke from overheating (thermostats were both stuck), so I need to get a hose on it to test if the upper grommet is leaking.

Worst case scenario, how hard is it to lift the power head? Seems pretty straightforward if I get a hoist, but I imagine a lot can go wrong (seized studs, broken bolts)...

 

[sutor623]

Depends if it has been run in salt. If shes salty, it may be more trouble than you would think.

Pulling the powerhead is a pain for sure. You will definitely need a hoist with that big powerhead. Will have to separate all of the controls, fuel/oil lines into the motor etc. and separate the lower cowling. If you are lucky you will be able to leave the powerhead fully dressed, but it will tell you, it will surely take some effort to remove the old powerhead gasket from the head and adapter plate. These things are made to adhere when heated so they are really stuck on there.

Once that is up and off, you will have to remove the adapter plate from the midsection, then you can remove the water tube and change the tube, grommet and gasket that is under the adapter plate.

Make sure to get a manual for reassembly. There are some special products that you will need to use upon reassembly, and TORQUE VALUES must be perfect!!! Do NOT attempt this, or even start it without a manual.

Will likely take you a solid weekend of work, maybe two, but very doable for the DIYer that has a motor hoist.

 

[rapishorrid]

Couldn't I leave all the controls/lines attached to the powerhead? With a hoist I'm imagining that I'll be able to lift it up a few inches and then move it towards the starboard side (where the controls and lines come from) until I have enough room to get at the adapter plate. I'd leave the motor hanging on the hoist right there with everything attached.

Also the motor has lived at a saltwater mooring for 26 years...

 

[sutor623]

Trust me trying to save time like that is just going to make it that much easier to break something and cost that much more. How long will it take to remove the fuel line, oil line and linkages??? And like I said, removing the old gasket from the powerhead is no easy chore. You will need to get good leverage on it, and maybe even set it flywheel down on a shop surface. You will also need to remove the adapter plate to get to the water input line and grommet. I took the entire midsection off the two hinges so I could work on it in my shop.

Not to mention you will need to remove the lower unit to do this job also. Some have left the lower unit on, but I dont think I would do it that way.

 

[rapishorrid]

Point taken, thanks for the info. As far as fitting an extension to the broken pipe goes - do you think a sharkbite or compression fitting would work?

 

[sutor623]

Yea I think a sharkbite would work great. Just as long as alignment is okay. I'd try to fix it rather than pull the powerhead if I could avoid it. You are looking at probably 15-20 hours to pull that powerhead and midsection and get it all back together.

 

[rapishorrid]

Not sure how good of a seal I'll be able make since I won't be able to smooth the end of the still attached pipe, but I'll give it a go this weekend and see what happens.

 

[sutor623]

No Title

Just use a copper tubing cutter from the hardware store and that end will be so smooth and pretty you wont have any issues at all with the sharkbite.

 

[rapishorrid]

Doubt I'll be able to fit one up there:

Will try that though. If not I can at least round out the pipe with a dowel and maybe get a deburring cylinder up there to smooth it a bit.

Hopefully there's enough room before the pipe curves to fit the sharkbite on.

 

[sutor623]

How did that break off, by forcing the lower unit up there when it wasnt in place? Also, it doesnt really look like there will be enough room for the sharkbite to grip. Just not enough straight surface to grab a hold to .

 

[sutor623]

Maybe you can get a dremel and cut up higher than the bend, slip on the bite, then bend a new copper line accordingly and leave enough flat at the top to grip the other end of the sharkbite?

 

[rapishorrid]

Motor was overheating and had a weak tell tale so I pulled the lower unit to find the bottom of the pipe dangling by a thread. Fell off when I touched it.

Both Tstats were stuck, so I think that caused the overheating which then caused the pipe to crack.

The chamber tightens up past the visible area in the photo. Will have to see what I can fit up there this weekend.

 

[oldboat1]

Just a thought now, but might be able to slip a fuel hose or similar up over the tube, and make a union with the hose. With the right diameter hose (I.D.), would think you could get a secure joint.

 

[rapishorrid]

Just a thought now, but might be able to slip a fuel hose or similar up over the tube, and make a union with the hose. With the right diameter hose (I.D.), would think you could get a secure joint.

Any downsides to this (not being able to withstand psi, heat, etc)? Assuming I can get the hose and a clamp on the pipe pictured - I'd then cut the broken pipe down, connect it to the water pump and then connect the hose to that with a clamp.

 

[interalian]

Trying to visualize how a rubber hose patch would work. Say you could slip it onto the stub up in the leg and clamp it there, then attach another copper pipe to the other end of the rubber hose where it goes into the pump. I would think the rubber would be flexible and the assembly would blow apart under pressure.

 

[oldboat1]

not sure I'm following about cutting down the pipe. Unless it's kinked up, I would butt up the copper tube inside the hose for rigidity. If a section is unusable, I might replace that. A long section of stand-alone flexible hose is probably not a good idea as the tube has to remain in place at the grommet (lateral movement a potential problem). You could wrap and clamp a stand alone section of hose with an aluminum sheet (roof flashing or something similar) for rigidity. I've patched a high pressure A/C hose in one of my old Mercedes that way (hose, epoxy, aluminum sheeting, and clamps) -- worked for years (much more stress on the patch than an outboard water supply tube, in my estimation).

Depending on what room you have, can use a couple of hose clamps, but may not need them. I've patched in a 5" extension this way, converting a smaller motor to a long shaft -- worked out fine. Temps didn't appear to affect it. Check it when servicing the impeller. (Should add for clarity that I was patching in a 5" section I had cut off when initially converting the motor to a short shaft -- similar to what you would be doing, I think. As I recall, I did clamp each end of the hose patch in that case -- but might have worked just as well without clamping.)

 

[rapishorrid]

not sure I'm following about cutting down the pipe.

I was referring to cutting down the 8" piece of pipe that broke off the one in the picture and sticking it in the water pump. Then patching a few inches of hose between the two pipes.

 

[interalian]

OK, I get it. Use a short length of rubber heater hose to create a splice, and have another bit o copper below to keep it all rigid. Might work. No idea if you could tighten hose clamps up there.