old johnson, old questions

[tracker79]

Got a johnson td-20 610586. I believe it to be a late 40`s. Gonna need a carb kit, paint & a decal set, any 1 source shops out there? I was told these engines run 16:1 with sae 30w oil, does this mix hold true with todays 2 stroke oil?

 

[tashasdaddy]

Re: old johnson, old questions

Welcome to iboats, and i hate to send you to another forum. but the best advice for that motor is going to be here: http://www.aomci.org/links_page/aomclnks.htm

 

[wbeaton]

Re: old johnson, old questions

I believe your motor is a 1947 Johnson 5 hp. 24:1 mix using 87 octane gas and TCW-3 2 stroke oil.

 

[JB]

Re: old johnson, old questions

TD-20s were made from 1947 to 1949.

Ditto WBeaton on the fuel mix.

Plugs are Champion J6J (J6C is the correct replacement) gapped at .030" for general use, .040" for extended trolling.

Set the points at .020"

 

[tmcalavy]

Re: old johnson, old questions

wbeaton is correct, but I wouldn't run it on a 24:1 mix even with modern TCW-3 marine grade oil....if you want to keep it alive. Johnson recommended a 16:1 mix, 1/2 pint of oil per gallon of gas, when new...but that was straight grade auto motor oil, not TCW-3. The modern oils are much better but those oldies but goodies do not have roller bearings...they use bushings that rely on a film of oil/lubricant to keep metal surfaces apart...why take a chance on a 24:1 mix if you want to keep it alive...run the factory spec mix. Your call, just my 2 cents.

 

[tracker79]

Re: old johnson, old questions

Thanks for the input, My grandfather bought it new and always used 30w and it still runs a-1, I guess i`ll stick with it.

 

[Scaaty]

Re: old johnson, old questions

I'm going to disagree here...24-1 is fine...run 20-1 if paranoid. The old 30wt days at 16 are over. But if it don't smoke ya out or foul plugs, what the heck...

Decals and paint here. Decal link at bottom

http://www.nymarine.ca/

Carb stuff here..click Johnson, scroll down to Fuel Systems

http://www.laingsoutboards.com/

 

[JB]

Re: old johnson, old questions

I don't think you are taking any chances running 24:1 with TC-W3 in your TD.

That is better than the mix OMC specified (TC-W at 24:1) for all pre-1964 OMC engines (in 1964).

They wouldn't have made that change unless they knew it would work.

 

[tmcalavy]

Re: old johnson, old questions

To each his own...if it were mine and I valued it as an antique, especially with sentimental family value, I'd run at original mfg. spec regardless of later bulletins, etc. Oil is cheap and you can't replace a 50+ year old bushing after it's hosed...nor the motor.

 

[Scaaty]

Re: old johnson, old questions

I wish FR or Chinewalker would chime in here on the oil mix...those 2 know the old motors. Parted out a lot of TD's and TN's, never ripped one down (they never needed it..either froze from neglect or spun/run). Know the QD's ran rollers (small end plain..think CD's did too), so if they do have plain big end shells, well, I still see no prob with 24-1. Of course, this is an oil question, so I'll sit back with the Popcorn..
I will post new and ask about the bearings...curious myself.

 

[Scaaty]

Re: old johnson, old questions

To each his own...if it were mine and I valued it as an antique, especially with sentimental family value, I'd run at original mfg. spec regardless of later bulletins, etc. Oil is cheap and you can't replace a 50+ year old bushing after it's hosed...nor the motor.

Problem here is they are so fixable, parts all over, and the comment of original mfg. spec is well, oil and those suggestions are almost 60 years old. Engine design is basically the same as today, tolerences just about the same, and even if plain bearings, its the oil film strength that separates moving parts. And the oil today is superior to the old 30wt Dino oil

 

[tmcalavy]

Re: old johnson, old questions

Valid points. Still believe that bushing is not a bearing and should be treated/run according to original mfg. specs, especially if you want to keep that old antique around for the next generation. Guess I don't trust much of the modern stuff completely...since I read China/Pakistan/Indonesia and other locales on the Made In labels. Oil could be next.

 

[BoatBuoy]

Re: old johnson, old questions

From the Evinrude website:

"Q - What is the fuel/oil mix for my motor?

A - The following is generally true: 1958 and prior used 20:1, 1959 thru 1963 used 24:1, 1964 and newer use 50:1. High performance usage (racing) requires a ratio of 25:1. New engine break-in (not DI) requires 25:1."

 

[tmcalavy]

Re: old johnson, old questions

Valid instructions direct from Evinrude. Course the older you get the more you appreciate more lube, in more ways/areas than one...keeps worn parts working without creaking.