Re: evinrude year/mix ratio???
18302 is the model number, indicating the engine is a 1963 18hp Evinrude. Mixture is 50/1 as powerhead incorporates "all" needle, roller, and/or ball bearings.
6602E is the model number which indicates that the engine is a 1966 6hp Evinrude. Mixture used is normally 24/1 as most powerhead bearings are the babbit/bushing type. However, there are thousands of these engines using the 50/1 mixture with no ill effects. I myself have used that 50/1 mixture on the various year 6hp engines and have encountered no problems.