l have an 12.0 hp Sea king that is from the late 60's. This is the first outboard l have ever owned, it didnt come with a manual. It runs but it is ruff running, do l need to add oil to the gas and if so what is the mixture that l need to make it the model # is GG8971A. Any help would be appreciated

..sea king is/was made for sears...first. change plug..get a can of carb cleaner and spray inside and out..check/clean air filter.. a ratio of 30 to one should be safe. if its blowing blue smoke cut back to 40 to one..and so on

here is the thing about carb cleaners & two-stroke engines.

as u know, 2-strokes get their lubrication from the fuel. carb cleaner has no lubricating qualities, but it is an excellent solvent.

anything sprayed down the carb throat of a 2-stroke outboard goes straight into the cylinders, where it strips the oil right off the walls.

if u would not run ur motor without oil, do not run it on carb cleaner.

outboard carbs r amazingly simple devices, yours probably has two circuits, adjustable slow-speed jet, & the fixed jet might be fixed. A bowl, a float with valve, needle & seat.

take it apart & soak it, find the right kit for it. u will be glad u did.

somebody over on the repair forums at http://forums.iboats.com will be able to hook u up with a manual

30:1 is probably safe until u find out for sure. u could go as rich as 24:1 if u wanted.