Repowerd my 1989 22' Chris-Craft center console with year 2000 200hd. horse power Evinrude ficht outboard. Is the gas you buy with 87% octane okay for these engines or do you need octane boster added. This engine was bought from a west coast city with their lifeguard sevice Good maintance all the 12 years they owned then. Only 600 hours when bought. Any other info on these engines would be helpfull also.