My RDS-26R project (’64 40 hp) questions

[amuller]

I’ve pretty much torn this down enough to see what I have.

The powerhead seems fundamentally OK so far. Has electrical glitches and sheared key/greased taper. No big deal that I can see. One minor question: it has one green German coil about 4.6 K ohms, and one black OMC coil about 7 K ohms. I expect they both make sparks, but does anyone think it important to have matching coils?

The gearcase, though, is pretty much toast. Water sat it in. Gears aren’t visibly pitted but are stained and a bit rough. Pinion and its roller brg are sadly damaged. ball bearing and tapered roller bearing are not good but these look to me like common and cheap industrial bearings. Dog clutch looks OK to me. How heavily loaded are these gears? Could put the thing together and it would feel nice and smooth, but I doubt it would last.

Freeze crack in skeg to top it off–which I missed and should not have while buying it.

In any case (pun?) I want to get rid of the 5" extension.

So all this windbaggery is by way of asking how close I need to get for a parts motor. Are these RD gearcases pretty much the same in strength and ratio? What years would work? Is there a problem combining the fancy double-layer leg with an ordinary gearcase? Not that I can see, but…..

This is not a job that needs to get done tomorrow, but I want know what to look for.

Thanks for any insight.

[chris-p]

You have a few options here, but the gearcases are common enough, I would simply buy a donor gearcase, rather than piecing together all the parts you need, read expensive that way!

[ADAM GIBB]

Chris,
I may be wrong, but I think that all of the super quiet gear cases have the two water line pump and the single wall have the older one water line pump. Not sure if you can just swap the whole pump housing. But the later ones are plentiful.

[johnny-infl]

where are you located ?
I have a complete ’62 40hp Super Quiet long shaft if you can come and get it,
arrange for a pickup or pay shipping from Central Florida
(the whole motor – will not part it out).

[frankr]

To answer the question, the super quiet (double wall) gearcases will not interchange with the single wall ones.

[amuller]

quote Johnny_inFL:

where are you located ?
I have a complete ’62 40hp Super Quiet long shaft if you can come and get it,
arrange for a pickup or pay shipping from Central Florida
(the whole motor – will not part it out).

I’m in Minnesota.

[amuller]

quote FrankR:

To answer the question, the super quiet (double wall) gearcases will not interchange with the single wall ones.

What are the differences aside from the pump and water tubes?

[johnny-infl]

When removing the 5" extension, you found two 14" brass water tubes.

in my world, I am going to just cut off 5" from the top part of the water tubes, (measure 3 times, cut once)
already replaced all the appropriate seals and gaskets with new,
install the correct size drive shaft and I cut the shift linkage to fit the short and put it all back together.
The two 40s I am working on now are "almost" completely rebuilt – – – but, my home move really
put a plunker in my piddling !!! no room for nothing. so they are on the back burner for ahwile.

I found all the parts needed to refurbish the gear case on e-bay or Marine Engine.
purchasing the RDS Parts Catalog from e-bay was essential.
Marine Engine has the same manual on their website: http://www.marineengine.com/parts/johns … case+Group
The water pump and grommets will remain the same – just shorten the water tubes, drive shaft and shift linkage.

disclaimer: I am in no way a mechanic !!! I am a complete novice to the Big Twins and learning as I go.

good luck

[amuller]

Thanks, Johnny.

I’m entirely new to these Big Twins.

Yes, it looks like the two water tubes can be easily enough shortened, or made up new. I have the 6" brass shift rod coupler, which looks like it can be shortened or replaced. My gearcase is toast. Hoping someone will give the details on why a single-wall gearcase won’t work.

Buying a parts catalog seems like a good idea as the listings on Marineengine are confusing me. I have a handle on a ’57 parts motor but don’t know what would be usable.

Anybody know if it works out to swap the skeg onto another case? I tend to think they are bored as a matched pair but don’t really know.

Alan

[johnny-infl]

yes, if you have the 6" brass shift rod connector, just purchase the shorter version. (no need to replace the linkage).
also, when it comes time to look for a short drive shaft, ensure the splines match.
some shafts "appear" to be identical, but the O-Ring groove may be different and
the spline length may be different. also, the woodruff key for the impeller may be different.
It could be a key or a round pin.
attached are photos of the regular Sea Horse and the Super Quiet Sea Horse.
disregard the 33hp as it is only to clarify how the water pumps are different.
I have gained this knoweldge thru trial and error – mostly ERROR….
spending a lot of money on parts that are not a correct fit is very frustrating.
Having the parts catalog will make your project much, much easier.
I’m not sure who told me or where I read it, but, 1960 was the turning point to change a LOT of parts
for the Sea Horse that are not interchanagable with 1959 and back ……. I personally would be leary of a 1957 model.
I changed out one skeg with a different model that fit – – – smooth sanded the mating surfaces, new spaghetti seal
and black sealing gasket material….. all fit well.

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