1954 Johnson RD-15 Cooling system

[Rockriverine]

I just bought a 54 Johnson RD-15 25 Hp on eBay.

I have seen some reference to the " water tubeless" design on the lower unit. I'm not clear on how that works compared to the water pump tube I see on my 58 FD-12. Any clues.

Also, in general, I know the RD's changed style in 1955. Other than the cowl, 12v start and adding a water tube, how interchangeable are parts from 54 to 55? I know for example the tiller arm gear is different.

Seems to be more 55's out there for mining parts.

Thanks.

Steve

 

[racerone]

Re: 1954 Johnson RD-15 Cooling system

The water is fed by channels to a tube that is cast right into the exhaust housing.--Also done on a number of newer motors.----Done on the 25 / 35 HP 3 cylinder models and on the 50 HP models after about 1990.

 

[HighTrim]

Re: 1954 Johnson RD-15 Cooling system

You have a '53 25hp, not a '54

Being a '53, you wont have electric start issues to worry about. The electric start was introduced in '54. In '55 suspension drives were added.

The 12 volt system did not start until the '57 35hp. In '54, '55 and with the '56 30hp, 6 volt systems were used.

So, I guess we should figure out exactly what you have before determining what can be used where. Either the year, or model number are wrong.

Parts are still easily had for any of the years. Posting wanted ads at aomci.org in the webvertize usually turns up a few good offers.

 

[HighTrim]

Re: 1954 Johnson RD-15 Cooling system

Here is something to show the flow from the pump to the water tube.

 

[Willyclay]

Re: 1954 Johnson RD-15 Cooling system

Maybe you can find some answers in the old Johnson manual at the link below. Good luck!

Boatinfo - 1922-1964 Johnson Service Manual

 

[Rockriverine]

Re: 1954 Johnson RD-15 Cooling system

Great incites.

Thanks to all.

 

[Rockriverine]

Re: 1954 Johnson RD-15 Cooling system

You have a '53 25hp, not a '54

Being a '53, you wont have electric start issues to worry about. The electric start was introduced in '54. In '55 suspension drives were added.

The 12 volt system did not start until the '57 35hp. In '54, '55 and with the '56 30hp, 6 volt systems were used.

So, I guess we should figure out exactly what you have before determining what can be used where. Either the year, or model number are wrong.

Parts are still easily had for any of the years. Posting wanted ads at aomci.org in the webvertize usually turns up a few good offers.

Motor was an eBay purchase ( should arrive Monday) Going on listing info. Photo does show battery cables coming out the front, so it BETTER have a starter. The downside of online purchases. Either way, looking for the challenge of the renovation.

 

[HighTrim]

Re: 1954 Johnson RD-15 Cooling system

Hopefully he had the model number wrong? If it was a RD15 though, it wont have electric start. The first electric start would be the 1954 RDE-16(a)

I am assuming you had hoped for an electric start motor? Do you have any pics of the inside of the cowl? Did you save any of the pics? Post them and we can tell you with surety what you have.

 

[racerone]

Re: 1954 Johnson RD-15 Cooling system

Hope it was not an electric toy motor.

 

[HighTrim]

Re: 1954 Johnson RD-15 Cooling system

Hope it was not an electric toy motor.

Now THAT would be the misunderstanding of the century, lol!

 

[Rockriverine]

Re: 1954 Johnson RD-15 Cooling system

Hopefully he had the model number wrong? If it was a RD15 though, it wont have electric start. The first electric start would be the 1954 RDE-16(a)

I am assuming you had hoped for an electric start motor? Do you have any pics of the inside of the cowl? Did you save any of the pics? Post them and we can tell you with surety what you have.

Here are two of the photos from the listing.
Note the front view with battery cables coming out from under the cowl.

She have unit shorty and solve mystery.

 

[racerone]

Re: 1954 Johnson RD-15 Cooling system

That must be a 1954 -----You might have to rig up a box with a solenoid and a bit of wiring.---------Very strong and long lasting motors.---------Lower unit gears / bearings can be considered heavy duty compared to some new motors.

 

[HighTrim]

Re: 1954 Johnson RD-15 Cooling system

The decals look more '53ish, maybe it was added after the fact?

Would like to see more pics and a model/serial number when you get it!

 

[Rockriverine]

Re: 1954 Johnson RD-15 Cooling system

Well the UPS fella showed up today with an old outboard.

Per the ID plate (see photo) it is indeed and RD-15.
It is also electric start.

Note the other two pictures.
Looks like it was an after market conversion.
Quite a site.

A chain drive starter. Not sure how the starter gear would disengage upon ignition and keep the starter
from running 4500 rpm or whatever they do.

In the conversion, they did away with the pull start mechanism completely.

Note the bracket that holds the starter in place. It's cut out of aluminum plating as opposed to the cast brackets from OMC.

No choke solenoid.

On top of that, the intake manifold has a 2 inch crack about a 1/16" wide.

So...not really what I was expecting. Probably won't be going on my boat, but I find it kind of fascinating and a tad frightening at the same time.

In general, it looks like it has not been run in many moons.
I had to put heat on two of the 10 cowl screws to remove it.

I doubt the seller ever ran it or had the cowl off.



Anybody want a one of a kind?

 

[racerone]

Re: 1954 Johnson RD-15 Cooling system

Perhaps there is some sort of clutch mechanism built into this.-If not then the rpm of the starter would be scary at full throttle.

 

[Vintin]

Re: 1954 Johnson RD-15 Cooling system

Any chance it's a starter that after starting acts as a generator?

 

[HighTrim]

Re: 1954 Johnson RD-15 Cooling system

Hmmmm,

I have to say, I have never seen that before. Well now we know for certain what we are dealing with!

 

[Chinewalker]

Re: 1954 Johnson RD-15 Cooling system

Let me know if you need a new intake plate - I've probably got one...

 

[nwcove]

Re: 1954 Johnson RD-15 Cooling system

Perhaps there is some sort of clutch mechanism built into this.-If not then the rpm of the starter would be scary at full throttle.

very creative design with the chain drive! i would surmise that it still uses pawls of some sort to engage the flywheel (hard on gear tho!). cant wait to see what has been done tho.

 

[HighTrim]

Re: 1954 Johnson RD-15 Cooling system

So I found out from fellow AOMCI members that it is an aftermarket accessory. Not home made at all. Ive never seen one before, that is for sure.

If you could Rock I would be interested in some good pictures of this. There is an AOMCI member that I know that is writing an article on RD accessories for the Antique Outboarder magazine and would like to use your pics in his article. PM if interested.