Motorgeek, can changing oil type and mixture ratio help make you run richer or leaner? Say going from synthetic amsoil 25:1 to 927 castor 32:1? Does less oil, higher ratio mean more gas and a rich condition if your jetting was dialed previously?

In theory and internet folk lore, putting less oil in the fuel does richen the air/fuel ratio..................BUT............

oil is fuel and the heating value of most oils are so close to the heating value of gasoline it really does not hardly make any difference in the real air/fuel ratio.

The heating value and jetting can vary more from one brand of race gas to the next brand of race gas than changing from 25:1 to 32:1 premix ratio using the same brand of race gas.