1955 Johnson RD-17S 25hp Restoration

jb93

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Compression checked out 90/100, so I brought it home. Came with 2 line tank, Evinrude Simplex controls with cables and also the original 1955 Owners Manual. Flywheel popped off very easy...too easy...and the flywheel nut was not tightened to spec. Ignition has been into at some point with newer coils and condensers. The coils look to be in good condition, except the wire coating has been worn through in a couple of areas. Should I replace the coils or OK to use some liquid tape to repair?

Carb is soaking tonight. Got all my parts on order today, so should be in business by end of next week.

I promise that I will post some more pics once the ice melts here in Dallas and I can wash it up a bit.

 
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HighTrim

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Re: 1955 Johnson RD-17S 25hp Restoration

If it is not right into the wires themselves, you can heat shrink it, or I suppose liquid electrical tape.

I just did a RDE 17 for a fellow. Finished making the new wiring harness tonight.

Have a good look around, even the flywheel itself.

Very often I find that when a flywheel is just popped on quick, there was a reason. May not be the case here, but regardless give her a good inspection.
 

boobie

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Re: 1955 Johnson RD-17S 25hp Restoration

I'd probably replace the wires with new. Less trouble in the long run.
 

jb93

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Re: 1955 Johnson RD-17S 25hp Restoration

I'd probably replace the wires with new. Less trouble in the long run.

How do I replace a wire on a coil, since it is potted into the coil body itself? Do you mean cut and splice?
 

HighTrim

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Re: 1955 Johnson RD-17S 25hp Restoration

You cannot replace the wire. I cannot tell from the pic, has it worn right through the wire itself? If so replace. If not, protect it and it will not affect a thing. A mechanic will tell you to replace it, but Ill leave that decision up to you.

I think I bought over 50 Universal Coils last year. That is just to replace the ones that were original. If I would have replaced them all with worn ground wires it would have been 100, lol.

Just be sure to pull the wire in tight to the coil before you tighten it down so this doesn't happen again.
 

jb93

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Re: 1955 Johnson RD-17S 25hp Restoration

A little disappointment tonight. Cleaned up the old points, liquid tape on the worn coil wires, new plug wires. Set the points at 0.020 with the rubbing block centered on the word TOP of the cam. No sparkey...darn! :grumpy: I have a tune up kit of points and condensers in route. Will swap those out and give it another go. If no joy then new coils.

I am setting the points correctly...yes? With the rubbing block on the "O" of the word "TOP" on the cam.
 

HighTrim

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Re: 1955 Johnson RD-17S 25hp Restoration

Set it at the widest point on the cam, usually at the flywheel key. The TOP just indicates which way to flip the cam.

The points may need dressing. I fold wet/dry around a hacksaw blade if I don't have a points file handy, and run that through a dozen times. Blow off with compressed air. Then dip a business card or the like in acetone and run that through to clean.
 

jb93

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Re: 1955 Johnson RD-17S 25hp Restoration

Set it at the widest point on the cam, usually at the flywheel key. The TOP just indicates which way to flip the cam.

The points may need dressing. I fold wet/dry around a hacksaw blade if I don't have a points file handy, and run that through a dozen times. Blow off with compressed air. Then dip a business card or the like in acetone and run that through to clean.


Dressed points. Rechecked points gap. This time I get spark on one cylinder about every 3rd pull, sometimes a couple of times in a row. The other cylinder sparked 3-4 times in about 25 pulls. Marginal progress I suppose. I've got a tune kit that is supposed to deliver tomorrow, so I will put on new points and see what happens. If all works, I will remove old condensers and put them in my backup parts drawer and go ahead and put on the new ones. I'd just like to verify if they are good so I will have a known spare available if needed in a pinch.

Here are a few before pics. I've already removed the lower unit. She's a little rough on the exterior but not bad. Very clean under the cowling. I think she likes me. :couple_inlove:





 
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Chinewalker

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Re: 1955 Johnson RD-17S 25hp Restoration

That intermittent spark is almost surely dirty points. Have you installed the new ones yet?
 

HighTrim

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Re: 1955 Johnson RD-17S 25hp Restoration

Agree with above ^^^^

Keep dressing/cleaning or install new.
 

jb93

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Re: 1955 Johnson RD-17S 25hp Restoration

New points and condensers. First try intermittent spark. Cleaned points with acetone and business card...2nd try still intermittent spark. Dressed lightly with 600 grit and then acetone. Bam. Sparking good. I did note that if I didn't give the recoil a pretty firm pull it might only spark on one cylinder. If I give it a solid pull it sparked both consistent zap. I think I am good here now. Thanks.

Rebuilding carb next and I have a question. My part diagram shows a nipple of some sort on the right hand side of the intake manifold. Not the bottom center of it where the fuel hose is connected. Just to the right and above that.

My manifold has a short piece of hose with a screw in it. It doesn't look factory issue. What's going on here...see pic?

 
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HighTrim

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Re: 1955 Johnson RD-17S 25hp Restoration

That hose goes to the vacuum cut out switch, which will be located directly in front of it when you reinstall the mounting bracket.

It shuts down a cylinder when it senses high vacuum in the intake manifold, as in a broken shear pin for example.
 

jb93

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Re: 1955 Johnson RD-17S 25hp Restoration

That hose goes to the vacuum cut out switch, which will be located directly in front of it when you reinstall the mounting bracket.
It shuts down a cylinder when it senses high vacuum in the intake manifold, as in a broken shear pin for example.

I haven't removed a mounting bracket.
Vacuum cut out switch assembly must have been removed by a previous owner? It just had a bolt in the end of the hose as shown.

I see 376442 on my parts diagram listed as cutout switch assembly. Is that complete to bring my back to spec? Is it needed?
 

Chinewalker

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Re: 1955 Johnson RD-17S 25hp Restoration

I would install one - hit a log and shear a pin and you'll be in rev city. The cut-out prevents the motor from running away to the point of grenading on you.
 

HighTrim

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Re: 1955 Johnson RD-17S 25hp Restoration

I might be able to help with the switch if you cannot find one.

I went down and took a couple pics of a RD17 in my basement.

001.jpg002.jpg
 

jb93

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Re: 1955 Johnson RD-17S 25hp Restoration

I might be able to help with the switch if you cannot find one.

I went down and took a couple pics of a RD17 in my basement.

View attachment 219252View attachment 219253


Thanks for the pics. I found a used vacuum switch assembly for $15. What size hose is used to connect to manifold...can I just use a fuel hose? Also, what should I use for the rest of the hoses under the cowl...cannot find that in my parts listing. Thanks.
 

HighTrim

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Re: 1955 Johnson RD-17S 25hp Restoration

Just 3/16 fuel line will be fine. It is readily available anywhere.
 

jb93

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Re: 1955 Johnson RD-17S 25hp Restoration

Top and bottom 4 head bolts came out easy. The middle top between cylinders are stuck. I sure don't want to break them. Any advice?
 

HighTrim

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Re: 1955 Johnson RD-17S 25hp Restoration

Heat and cool cycles with penetrating oil in between.

Why are you taking the head off? New gasket?

While it is off, dress the head before installing new gasket. Coat bolts with Gasket Sealing Compound. Torque to 110 INCH/lbs for a full rotation, then again for the final 220 INCH/LBS for the final sweep. Tighten in the fashion posted below. Starting in the center spiralling outwards. Note I said INCH/LBS, that is only 18 to 20 ft/lbs at the end, but I prefer to use an inch/lbs wrench for this, more accurate if you have one.

Surfacing.jpg
TorqueSequence.jpg
 

jb93

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Re: 1955 Johnson RD-17S 25hp Restoration

Heat and cool cycles with penetrating oil in between.

Why are you taking the head off? New gasket?

While it is off, dress the head before installing new gasket. Coat bolts with Gasket Sealing Compound. Torque to 110 INCH/lbs for a full rotation, then again for the final 220 INCH/LBS for the final sweep. Tighten in the fashion posted below. Starting in the center spiralling outwards. Note I said INCH/LBS, that is only 18 to 20 ft/lbs at the end, but I prefer to use an inch/lbs wrench for this, more accurate if you have one.

View attachment 219329
View attachment 219330


Heat the head of the bolt or the aluminum part of the block where it is threaded into? Is a little micro torch enough heat?
 
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