Vintage Johnson question...from a modern Merc guy!

[JoeMan]

My friend has a '56 30HP Johnson outboard which he just got running after 20 years of sitting. According to the info he has on it, this motor originally had a 24:1 mix ratio using the lubricants available in 1956. He is currrently running a 50:1 mix ratio using Redline Two Stroke Racing Oil (synthetic). The engine runs quite strong, achieving 24 mph using GPS. The plug color is excellent. The Redline directions recommend mix ratios of up to 100:1 using
this lubricant. He is quite hesitant of going any higher than 50:1 in fear of creating too lean of a mixture. I am sure other folks have been running modern lubricants with old outboards and can easily answer this one.

Thanks!

JoeMan

 

[Chris1956]

Re: Vintage Johnson question...from a modern Merc guy!

Joe, The 24::1 oil mix was intended to protect outboards that had only sleeve bearings, versus needle bearings. I suspect that your friend has a sleeve bearing motor and will have that motor run really well and then seize immediately, if he continues with the 50::1 mix.

You might PM Joe Reeves and ask about that particular model and fuel mix. I think he will say 24::1!

 

[tashasdaddy]

Re: Vintage Johnson question...from a modern Merc guy!

if he wants that motor to keep running, he best go back to 24:1, the bearings in that motor are not made for the higher ratio. 24:1 TC-W3 outboard motor oil, he can use synthetic TC-W3.

 

[Chinewalker]

Re: Vintage Johnson question...from a modern Merc guy!

Agreed. The richer mixture does more than lubricate - it also cushions bearings and helps seal as there needs to be a film of oil in there that just isn't present on the lean mixes. Also, it is a straight up cooling system with no thermostat, so the tolerances can vary quite a bit depending on temperature. Keep the mix as per the original... 24:1.
- Scott

 

[JoeMan]

Re: Vintage Johnson question...from a modern Merc guy!

Guys, thank you. This is what I thought I would hear, but do not have the years of OB experience most of you have. Thanks for helping another boater avert a possible motor catastrophe due to previous bad advice!

JoeMan

 

[56 rude]

Re: Vintage Johnson question...from a modern Merc guy!

Let me add 2 more cents worth.I work on old motors exclusively ,for myself and other people ,stay with 24 to 1 for that year ,those motors love their oil.Ive been using xd-30 in my personal 18 (1957) sea-horse and have little or no smoke out on the lake.Currently working on a 1955 15 evinrude and a 1956 30 evinrude and will be recommending the same to the owner,24:1!