What octane gas should I be running in a Yamaha 200 Saltwater series II V6? This is my brother’s boat and every time I go out I like to bring 20 gallons of fuel in jerry cans as a thanks for the invite. My question is with a carbed engine like this what is the advantage of 93 octane? They only sell 93 at the dock at around $2.85 a gallon. I can get 87 for $1.88 at the corner station. <br /><br />Mac