Re: de-carbonating additives
I'm not sure what Yamaha calls theirs, but use it and follow the instructions EXACTLY. OMC's is called Engine Tuner. Use Yamaha's, Merc's or OMC's (Bombardier). They all work well. The best way to avoid carbon is use good oil, the octane they say (no higher) and set up the boat so the motor can achieve RPM's in the upper end of the range with an average load. Good luck!
