Tweet
Hello everyone, I have a 1978 Mercury (40) 4HP outboard 2 stroke, 2 cylinder. I called my local boat dealership for the fuel/oil ratio and they werent really sure off hand but that it was probably 50:1 ratio. I just bought a 3 gallon tank and some 2 cycle oil (1 pint 16 ounces) and needed to know for sure how much oil to put in the tank if i indeed fill up the 3 gallon tank?
-
-
The mixture for that outboard is 50:1 87 octane gas to TC-W3 rated outboard oil. That works out to 1/2 pint for your 3 gallon tank, or to say it another way 1/4 of your quart of TC-W3.
By the way, the plugs recommended for that engine in the US were Champion QL7J5 or QL7J gapped at .050". In the rest of the world, they recommended NGK RB6HS gapped at .050. I find the NGK ones work better in it. I don't use the NGK B6HS plugs because they cause a lot of radio interference, but they work equally well.
Comment