I am looking for the correct oil-fuel mix ratio for a WN-7A PowerMatic 12 outboard.

I believe it is 32:1, am I correct?

I am also wondering if that would be the same ratio for a WA-25.

Thanks in Advance,

Bob Herrick

AOMC Member
Texas Chapter AMOC Member

1956 Mercury spec sheet give ratio of 3/8 pint Quicksilver oil per gallon of non leaded regular gas...6 ounces of oil per 128 ounces of gas (fluid ounces)6/128 = about 21 parts gas to 1 part oil
Quicksilver Models (Racing) use 3/4 pint per gallon
Mercury Quicksilver oil and fully jeweled motors
ran a little leaner than the usual 16 to 1 ratio
of competition
With modern TCW3 and Synthetic Oils there are other
thoughts out there about what ratio an older motor
can be run with... when all is said and done oil and spark plugs are still much cheaper than
rings, pistons and bearings.

Thanks for the info.

-Bob

Can anyone tell me what the mix ratio is for my Wizard 6hp outboard? Thanks for any help/advice offered.

Mercury built Wizards from the 50's require the same lubrication. They called for 3/4 pint to the gallon, with the new superior oils I use 1/2 pt per gallon. I even run that premium Mercury or Johnson-Evinrude oil at that ratio in my fully modified racing Model Super 10 Wizard WM7-A & have made about 88 runs in the last two summers & the pistons & rings look just like when it was assembled. Also ran a 56 Champion Hot-Rod at least 150 runs with the same mixture turning 8000 rpm's with NO problems. When taken apart by Tom Moulder, the cross-hatch hone pattern was still on the cylinder walls. Plugs burn a nice soft light brown color with the proper heat range & carb high speed settings of course. NO fouling ever with this mixture.

2 more Cents added.

My dad had a 12 wizard (1954). The tank said 1 qt of oil per tank of gas. I think it was a 5 gal. tank.