Johnson TD20

[APL]

I just picked up a TD20 serial 602105 (any idea of the year?). I am aware that these are as common as they get, with that being said what issues do these motors generally tend to have outside of routine outboard maintenance items? This motor was last reportedly run a few months ago and looks to be in runnning condition as it sits now.

I appreciate anyone’s first hand insight..

[bobw]

That serial number should be a 1947 model.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

[APL]

Thanks Bob.

[aquasonic]

For maintenance, it’s up to you how far you want to go.

Carburetor- The carburetor should be completely dismantled, cleaned and rebuilt with new primer seals, and preferably a modified Mercury float. The plastic Mercury float is a simple ethanol resistant replacement for the original cork float.

Ignition wires- often times have crumbling insulation or missing connectors. If necessary, new copper core wires can be carefully soldered to the coil buttons.

Ignition components-it’s not uncommon that all ignition components are still good. Inspect all components and clean contacts. Clean and reset points.

Starter-remove the starter and inspect the three tiny pawl springs. If all three are in place and not bent or broken then consider yourself lucky, otherwise they can be made. You may also need a new rope or recoil spring.

Water pump/intake seal-A new water pump is a necessity. Also inspect/replace the water tube grommet/seal. These seals can degrade and swell when immersed in water effectively blocking off the cooling water. Some prefer to trim them, but replacement is even better.

http://pochefamily.org/outboard/ -Lots of good information here.

• This reply was modified 5 years, 5 months ago by aquasonic.
• This reply was modified 5 years, 5 months ago by aquasonic.

[aquasonic]

Maintenance can go as far as you want. Here are a few things to consider.

Carburetor-a cleaning and rebuild is in order. You will need new primer seals, and also a new float. A modified plastic ethanol resistant Mercury float is the best option here.

Ignition-inspect the sparkplug wires. If the insulation is hard and crumbling, new copper core wires can be carefully soldered onto the coil buttons. The ignition components are often times still good. Clean all contacts. Inspect/clean and reset the points. Lightly lube the points pushrods.

Starter- remove the starter and inspect the three tiny pawl springs. If one or more of the springs is missing/bent/broken, then new ones can be made. Ray Schaber wrote an article with directions on how to make them. Of course the starter rope and/or spring may need replacement. For peace of mind, it’s good to take the recoil spring out, inspect it, clean it, and re-grease it. One small kink, and it is a matter of time before it breaks.

Waterpump- a new water pump is a necessity. While apart inspect the housing and the elliptical. Behind the waterpump is the intake grommet/seal. These seals can degrade and swell effectively closing off the cooling water supply. Opinions vary some prefer to trim them, but replacement is even better.

[APL]

Thanks Aquasonic. Thoes are some good points, some of which I was aware of and some I wasn’t. That’s exactly what I was looking for.

[lloyd]

For new primer pump leather seals and instructions, Send $10.00 cash only and a SASE (self addressed stamped envelope) to: Lloyd Lautner, 9289 North Long Lake Road, Traverse City, Mich. 49685. More good info at:

pochefamily.org/outboard

Sorry that the price has increased to $10.00 but it is getting very difficult to find the proper oil tanned leather of the proper thickness. Hope that helps. Lloyd 231-929-7479

[APL]

Thanks for the Lloyd.. I will get that letter out to you this week. Although the primer seems to be funtioning now I am sure that with repeated use they are sure to fail. Thanks for making these available.

[csw]

check the compression, it needs to be 75lbs minimum to idle down.

[APL]

CSW: That’s good to know. From what I understand these motors originally were around 85psi.. This motor has good solid compression, from what I can feel. . I’ll have to get my compression gauge on it this week to see where it stands.

[Author]

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