1968 Evinrude Ski-Twin, Ski-Twin Electric 33 HP Outboards Service Manual, Page 2Get this manual
EVNRUDE OUTBOARD OL
We recommend using EVINRUDE OUTBOARD OILEVINRUDE OUTBOARD OIL is designed specifically for Evinrude outboard motor use at 50 to gasoline to oil ratio for engine break in and after break in, new and older modelsThis improved lubrication is formulated to provide additional benefits such as: exceptionallubrication, less varnish and combustion deposits, better spark plug good mixability with gasoline even in cold weather, and reduction of pre-ignition
If Evinrude Outboard Motor Oil should not available, see Oil Instructions Section 2-4