Fuel mix for my 1952 johnson 10hp sea horse

Blade_Link

Seaman
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Aug 4, 2009
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I was wondering what you guys would use for a fuel mix for this motor. i am currently running 30 maybe 40 to 1 ( gas is older but still good and some has evaporated) i was thinking of maybe running 25-1 what wouls you run to preserve this great motor
 

tx1961whaler

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Re: Fuel mix for my 1952 johnson 10hp sea horse

From www.evinrude.com :

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.
 

Blade_Link

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Re: Fuel mix for my 1952 johnson 10hp sea horse

thanks alot i guess i could have checked there haha
 

alangf

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Apr 12, 2009
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Re: Fuel mix for my 1952 johnson 10hp sea horse

From www.evinrude.com :

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.
I had one of these engines and if memory serves me it called for one quart of 30 weight non-detergent motor oil to 6 gallons of "white" gas. White gas, back then, was gas without tetraethyl lead compounded for marine use.
 

tx1961whaler

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Re: Fuel mix for my 1952 johnson 10hp sea horse

Yes, it called for 30 weight non-detergent motor oil back in 1952, but that was all that existed at the time. Now it's recommended to use TCW-3 two cycle oil @20:1
 

alangf

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Re: Fuel mix for my 1952 johnson 10hp sea horse

Yes, it called for 30 weight non-detergent motor oil back in 1952, but that was all that existed at the time. Now it's recommended to use TCW-3 two cycle oil @20:1
Thanks for the update. I'm sure the TCW3 is a better and cleaner burning lubricant. It has become difficult to find 30 weight non-detergent oil now. I don't use it in any of my outboards but lawnmowers and air compressors still use it. Boy! Am I getting out of date! I seem to have somehow gone straight from Clearacil to BenGay.
 

Blade_Link

Seaman
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Aug 4, 2009
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Re: Fuel mix for my 1952 johnson 10hp sea horse

im actually finding that my motor runs better at 35:1 good protection it works well
 

Chinewalker

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Re: Fuel mix for my 1952 johnson 10hp sea horse

BL - 35:1 simply isn't enough oil for your old 10hp. The 1950s QD models were noted for losing the wrist pin bearing, particularly when run lean on oil. The bearing was a phosphor bronze babbit bearing and they really need the extra oil. Acts as a cushioning agent as much as a lubricant...
 

jay mendoza

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Aug 14, 2009
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Re: Fuel mix for my 1952 johnson 10hp sea horse

The manual reccomends 1/2 pint of SAE 30W per gallon of gasoline, and they reccomend unleaded. That comes out to 16/1, which is what a bushing bearing engine needs to survive. I would be very leery to use anything less than 20:1, even with a modern TCW-3 rated oil. But I would use a modern oil (at the ratio reccomended by the manufacturer) as they are superior in dispersement, lubrication, low ash and have corrosion inhibitors as well. You cannot hurt it with too much oil, it will just smoke more, but you can easily spin a bearing and bust a rod with too little oil, don't risk it, play it safe.
 
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