It should be oil injected with a separate oil resivoir.
50:1
there should be a flat switch beside the cover for the gas cap, and the ignition switch. That is your choke. Sticking up is full choke, down is choke off.
If not using oil injection, the 115 hp Yamaha outboard will require a 50:1 ratio.
20:1
32:1 gas to oil mixture
50:1 ratio
30 liters of gas to 1 liter of oil
50.1
It would be wise to.At 32:1 ratio
the safest mixture would be 32 to 1
50/1
the kind at the pump, liquid perhaps...