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Watercraft Engine Maintenance

What is the fuel mix for Johnson seahorse 15hr?


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July 12, 2009 3:12PM

You do not indicate the year of manufacture. Many motors from the 50's by OMC have plain bearings. By 1960 all Johnson-Evinrude-Gale-Buccaneer (OMC) had full rolller and ball bearings. SO....

Motors before 1960 to be safe- use 24 to 1 mix. (1 quart oil per six gallons of gas).

Later motors use 50 to 1 mix. (16 oz. oil per six gallon gas, or 12 oz oil per 5 gallons gas)

Oil choices in order.

1. BEST CHOICE always--- An engine maker's branded oil. Examples: Quicksilver or Mercury (same thing) Evinrude-Johnson, Yamaha, Tohatsu, Nissan, Suzuki. Be sure it is 2 cycle type.

The engine makers oils are the most expensive. They are also 100% sure to exceed all requirements for outboard motors. Other oils are less expensive, often 1/3 the price. Major brands are reliable--- but may not be as good for long engine life. Some brands may not be OK. You will know if they are not OK when your motor needs major service or breaks down altogether.

2. A TCW-3 CERTIFIED oil. Most popular are Havolin, Exxon, Citgo, Pennzoil.

3. Some oils say TCW-3 rated. The makers do not get them certified. Don't use them.

4. Do not use chainsaw oils.

5. Never use an automobile oil.