I decarbonized my 1973 50 hp inline 4 two stroke on the weekend (left a nasty black ring around the boat after doing the "on the water portion"). Motor runs great, still has a thin layer of carbon on the piston tops, does anyone know if it's safe to use Johnson/Evinrude carbon guard--the stuff you add to the tank?<br /><br />I'm using Merc twc-3 oil, previous owner was using no name twc-3 oil.<br /><br />Can't get Quicksilver Quickleen or Valvtek products here in Canada.<br /><br />Thanks!
