1948 Johnson TD-20 5HP outboard technical info?

[karvanjon]

I have just acquired a 1948 Johnson TD-20 5HP outboard, but have no operating/servicing info about it. the motor seems to be in great shape and has good compression. The previous owner said it started and ran recently.<br /> I'd like some basic info about it before I attempt to start it (with the lower unit in a tub of water):<br /> What's the right fuel/oil ratio?<br /> What's the right spark plug type and gap? Point gap?<br /> How do I check/change the lower unit lubrication & what oil or grease should I use?<br /> I assume this has a water pump/impeller; where is the pump located & how do I check to see if it's working? Where are the water intake and exhaust ports located?<br /> What initial settings should I use for the idle mix needle valve adjustment and the rich/lean knob on the top?<br />Any help would be greatly appreciated.<br />

 

[JB]

Re: 1948 Johnson TD-20 5HP outboard technical info?

Ahoy, Joe. Welcome to the Board. You've asked a lot of questions. I can answer some, but maybe not in the order you asked.<br /><br />Fuel/oil mix: 24:1. 87 octane unleaded/TC-W3 rated oil.<br /><br />Spark plug: Champion J8J (Or modern equivalent) gapped at .030<br /><br />Points gaps: .020<br /><br />The water pump on the TD-20 is on the prop shaft and is accessed by removing the prop.<br /><br />I believe that crankcase oil is handled in the same way as most, my book doesn't say. There would be two screw-head plugs. The top is the vent and the lower is the drain and fill. The 90W oil used is thick enough that you have to open the vent hole as well as the drain to drain it. Then you pump it into the drain hole 'til it comes out of the vent, replace the vent plug, then the drain plug.<br /><br />Hope that helps. Let us know if you need more help.<br /><br />Red sky at night. . .<br />JB

 

[fone_man]

Re: 1948 Johnson TD-20 5HP outboard technical info?

Year / Model / Owner's / Parts / Service<br /><br />1946-49 / TD-20 / 301453 / 507789 / 302231<br /><br />Thsea are publications that can be had from Ken Cook Co on your model, go to this link...<br /><br />Ken Cook Co<br /><br />

 

[karvanjon]

Re: 1948 Johnson TD-20 5HP outboard technical info?

Many thanks for the great info!<br />do you have an answer for how to tell if the cooling water is flowing? I took a close look at lower unit last nite and saw two small holes in the shaft below the power head and above the lower swivel bearing. could these be the cooling water exit holes, or does it come out the exhaust?<br />Also, I saw a posting on "OLLIE's Board" which said to use Lubriplate 105 light grease for this motor's lower unit. What do you think about this and how would you change/add the grease in thos case? Dissambly and packing? seems like a lot of work!

 

[royw64]

Re: 1948 Johnson TD-20 5HP outboard technical info?

Water Pees out of a tiny hole in the Elbo of the water line to the water Jacket.

 

[Bear]

Re: 1948 Johnson TD-20 5HP outboard technical info?

Roy Williams is digging up some old posts everywhere

 

[Chinewalker]

Re: 1948 Johnson TD-20 5HP outboard technical info?

Hi Joe,<br /> I would use the Lubriplate grease, as I don't think that motor has lower unit seals, rather it uses bushings. Even if it does have rubber seals, they're over 50 years old! It would have originally called for the grease, go ahead and use it...<br />- Scott

 

[Bear]

Re: 1948 Johnson TD-20 5HP outboard technical info?

"Roy Williams is digging up some old posts everywhere."<br />This one was posted October 02, 2001.<br />That was october last year. <br />It is a waste of time to reply to that old post. I don't think Joe will see it. <br /><br />A waste of Chinewalker's time, Roy.