1963 75hp Water Pipe Questions

[yorab]

I have my powerhead adapter plate separated from the outer exhaust housing. I also have the water pipes disconnected from the adapter plate. When I reconnect the water pipes with new end grommets and gaskets, will the pipes be free to spin while still holding a good seal? I would imagine that they won't, but I know that some types of pipe connections allow for rotation of the pipes without leaking.

The reason that I am asking is that I see a difficult task ahead if the pipes don't spin. I need to screw them into place in the adapter plate and then I need to feed them down through the holes in the outer exhaust housing where they will then mate up with the appropriate grommets in the topside of the gearcase. I'm thinking that if the pipes don't spin, it gonna be a PITA to figure out exactly how to orient the pipes when I tighten down the coupler bolts. Any ideas or insight from anybody who has replaced their water pipes on a similar motor? Lastly, which pipe goes on which side? There is a shorty and a longer pipe. Thanks.

 

[Chris1956]

Re: 1963 75hp Water Pipe Questions

the shorter pipe is likely the output from the waterpump. The longer is likely the recirculating pipe.

 

[yorab]

Re: 1963 75hp Water Pipe Questions

Thanks Chris1956, that makes sense. The shorter pipe definitely goes into the water pump housing and the longer pipe goes down in behind the water pump housing for my motor. Now I just need to figure out where each connects to the adapter plate. In other words, does the longer pipe connect on the left side of the plate or the right side? Maybe it will be intuitive once I line things up. Or, perhaps it won't matter as long as a complete circuit is made. However, I'm not so sure about my last comment since there are check valves in the circuit in the thermostat housing and reversing the order of the pipes may severely affect water flow in the system.

 

[F_R]

Re: 1963 75hp Water Pipe Questions

Parts book shows the inlet (short) tube on the port side. The outlet (long) tube is on the starboard side.

 

[yorab]

Re: 1963 75hp Water Pipe Questions

A long post here but a lot to report. I'm stuck at a few key steps that are holding up what I think may be my final assembly of a 3+ year rebuild:


F R, I am thinking that the inlet pipe (the shorter one) is indeed on the port side as per the manual (pic 1), but I have a nagging suspicion that it may be reversed. Part # 31 is the Inlet Water Tube and part #33 is the Outlet Water Tube. I've found an error with orientation of the throttle plates (see my other post) and I feel that the manual could be wrong here. I'm not saying that it IS wrong, just that it COULD be.

I have taken hundreds of pics during my rebuild but I didn't get a clear pic of the pipe orientation. I have a pic that clearly shows the long and short pipes (pic 2), but I can't see which comes from the starboard side of the adapter plate and which one comes from the port. It's kind of difficult to see but it looks like the short pipe comes from the starboard side, opposite from what the manual shows. That is why I am questioning the manual.

Does anybody have a relatively similar motor with the LU pulled? If so, could you look to see which side the longer pipe originates from? This would clear things up immediately.

I have also posted a pic of my adapter plate (pic 3) and the bottom of my powerhead (pic 4). You can see that the water passage on the starboard side of the adapter plate lines up with the water hole for the exhaust plate passages. Just some thoughts that may help clear this up:

Does cool(er) water come up from the water pump then immediately go into the exhaust plate passages and then to the rest of the motor, or does the water travel through the exhaust plate passages last before returning down the outlet pipe? If the exhaust plate passages are the last stop for the water flow, then the longer outlet pipe must be attached to the starboard side of the adapter plate as the manual shows.

I really don't want to make this more complicated than it needs to be; I just want to be sure that it is correct so that I don't have to remove the powerhead again simply because I connected the tubes backwards. Thanks for your advice and input.

 

[yorab]

Re: 1963 75hp Water Pipe Questions

I've done some searching online and I found pics of two different exhaust tube and adapter plate assemblies. In both cases, the longer (outlet) tube was connected to the port side which is opposite to what the parts manual shows.

I'm trying to find somebody who is getting ready to pull their LU for an impeller replacement. I can then get a definite answer as to which side the tubes connect. As I said earlier, I don't want to make this more complicated than it needs to be, but I really, really don't want to break down the motor again if I reverse the order of the tubes.

 

[yorab]

Re: 1963 75hp Water Pipe Questions

Just to close this out, the input (shorter) tube connects to the port side as the manual shows. The pic that I took before disassembly was inconclusive and I'm not sure why the only two pics that I found online of an adapter plate with tubes show the pipes oriented the other way around.

I know for sure that the input connects to the port side because I connected a hose and ran water up the port side and the starboard side. The water wouldn't flow through the starboard side due to the closed pressure valve in the cooling system. When I connected to the port side, water flowed through the thermstat housing outlet tubes.

I also used an o-ring in combination with a grommet and a coupler gasket at the adapter plate end of the tubes. This made a leak-proof seal while still allowing the tubes to rotate which made it easy to feed the tube down through the exhaust housing.