TD 20 -NEED parts

[dheitman62]

I recently acquired a 1947 TD 20 Johnson Sea Horse. The motor is in really good shape but needs a little work. There was no spark so I opened it up and tested what I could. The coils seem ok. They have continuity anyway. The points however are black and pitted. I’m hoping to find somewhere that still sells them. I’ve looked all over the web and called all of my local go-to shops. Nothing.

Also, I found that oil was leaking out of the gear box almost as fast as I could squeeze it in. So, I need to find someplace to get seals and gaskets to correct this. Can’t find them either. Anywhere.

If any body knows where these parts may be available, it would help ALOT!!!

Also, maybe photos or videos of these repairs and/or exploded parts drawings would be very helpful.

I am mechanically inclined and confident I can make these repairs. But, I am also a "Follow the Recipe" kind of mechanic, so any literature, new or old, would be extremely helpful.

Thanks in advance for any help or advice…

[frankr]

Breaker points are part number 580016. marineengine.com has them, but you probably won’t want them when you see the price. Post a want ad on this website’s classified ads forum. The ad is free. There are lots of those points out there, new and used.

Having said that, I suggest you clean yours. Take them completely apart and polish each contact individually. Do one set at a time and be careful not to lose any of the many insulators. Doing one set at a time leaves you a sample for reassembly, just in case.

Somebody will correct me if I am wrong, but I think the TD takes grease in the lower unit, not oil.

[mercuryman]

Right its grease Lubaplate 105 of Johndeere Cornhead grease you want "0" weight not the thick stuff you use on cars.

[aquasonic]

The owners manual call for 90W gear oil. That is what I always use and it works. I don’t recall ever seeing one with LU grease.

[mercuryman]

I have a TD 20 and I just looked at foot a "GREASE" stamp is right by fill screw. The TN models with clutch may use 90 oil.

[garry-in-michigan]

It is important that the insolation be clean. dirty insolation bleeds the charge out of the capacitor reducing ignition output. (Just like leaking insolation in the capacitor.) Many find a breaker point file awkward to use. The sand in sand paper is silicone dioxide, an insulator. Follow up with a 600 grit wet-or-dry paper (which is bonded tungsten carbide) lubricated with WD40, followed by butcher paper to leave a clean surface. Some use a business card for the increased stiffness, but some of these cards use titanium dioxide as a whitener, which is also an insulator.

If the oil (grease prefered) gets into the water pump, it can cause the rotor to swell. This decreases the amount of water pumped and engine overheating. The models HD and TD have the carburetor by the exhaust manifold and overheating will cause vapor lock in these models.



If you run into carburetor problems, this will help –

That was one of Johnson’s largest selling outboards. . . 🙂

[49hiawatha]

Wow I wish somebody (Gary) gave me all that info @ the start! Frank R, Mumbles and Doug Penn helped alot. Keep the teaching going. 🙂

[dheitman62]

Many thanks to each of you. All of this information will make things go much more smoothly. I plan on disassembling and cleaning the points today. I’ll let you all know how that goes.

There is one thing that I am still not clear on: the gear box and what kind of oil/grease to use. I looked at the foot and there is no stamp at all by either the fill or the vent/level screw. Knowing how to change gear oil in my other motors makes me lean towards using oil. But, I have also seen the word "grease" used in the sparse literature I have to describe things like the seals. They are reffered to as "grease seals" (see attached image with the words circled) But everything else I have read says to use 90w.

I’m confused…

Also, Garry, the things you posted are so helpful that I can’t help but ask for any additional info you may have on the gear box and how to actually change seals, etc. as I said, I am a recipe kind of guy when it comes to motors. Thanks in advance.

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[frankr]

Believe it or not, the Johnson manual doesn’t say what grease for the TD models. Here are the TD pages for the gearcase
http://boatinfo.no/lib/johnson/manuals/ … .html#/384

[dheitman62]

Well, I found what looks like it may be my problem. In the first pic below, there is a red arrow pointing to an insulation strip that isolates one side of the points from the other. Looks like it’s made of Bakelite or something similar. The second pic is the other set of points. The red arrow points to a spot where part of that insulator is missing and there is contact. The points are thus shorted together. Could that stop me from getting spark? Would that stop BOTH sides from getting spark?

I am still going to take apart that side and clean it. The other points were a little pitted but I got them shiny again. I’ll

do the same for this side after I fix the broken insulator.

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