Red band ended in 1968 and blue band ran from around 1970 serial numbers are a more accurate method of determining year
A 65 hp Mercury outboard, serial number 3076063, would be a 1971 year model.
A 65 hp Mercury outboard, serial number 2604414, would be a 1969 year model.
A 65 hp Mercury outboard, serial number 3149254, is a 1971 year model.
1958
A 65 hp Mercury outboard, SN 6315551 would be a 1976 year model.
A Mercury 65 hp outboard, serial number 7039331 would be a 1974 year model.
You don't say which model year of Mercury Mountaineer but they have all used the ( BCI group size 65 battery ) such as the Motorcraft BXT-65-650
An 65 hp Mercury outboard, serial number 4266564 is a 1975 year model.
A 65 hp Mercury outboard, serial number 4574019, is a 1976 year model.
64 was last year on dimes quarters, etc. Compare a 64 & 65. You will see a copper band on ridged side of 65's & later.
65 days
In my area you can get Blue Bonnet 65% vegetable oil spread for about 65 cents at Winco.