You can do 24 or 25 to 1, as OBJ suggests or you can use the instructions that came with your motor's manual, as OBJ's tagline suggests. The manual for a 51 seaking suggests 16:1 or half pint oil (8 oz.) per gallon. Anything leaner than 24/25:1 may burn it up as the older iron uses bushings instead of bearings. Bushings function best and fail least often when they have oil to separate the moving parts...hence the richer mixtures than we use today with motors full of bearings.
Hey King, one more thing to add to Tim's post, do use a quality TCW-3 outboard motor oil. These are the ones marketed by Bombardier, Merc, Yamaha and others. Much Luck.
I recently purchased a sea king mod.#25GG-9015A, does anyone know the year and HP rating, it was sold to me as a 5 HP. the plate on the side uses a oil fuel mix of 16:1 for whoever is interested.
Freddy's right...you really should start a new thread. But...in the meantime, it's a 1952 5 hp Sea King made by OMC's Gale Division for Montgomery Wards. You reverse the first two numbers to get the year on the old Gale motors...either the numbers before the GG in the model number, or the first two numbers in the serial number (later models). Acme Outboards has a manual for 51-54 Sea Kings if you need one.
In 1964 OMC changed the recommendation for all OMC made engines (including Gale/Sea King) made before 1964 to 24:1 (comes out that way if you use a quart of TC-W3 to a 6 gallon portable tank) using TCW (Two Cycle, Water cooled) rated outboard oil.
The 16:1 recommendation assumed you would be using SAE 30w motor oil not specifically made for water cooled outboards.
I won't argue with OBJ about 24:1 vs. 25:1. After all we insist on calling a truly 48:1 mix (1 pint TC-W3 to 6 gallons) 50:1.
