The Perfect cure for carbon, is a perfect mix of fuel! To eliminate carbon you can add OMC Carbon Gaurd to your fuel. Sea Foam is a good preventive. But it does not prevent carbon. OMC will evaporate carbon as it tries to form., I ALWAYS run Synthetic 2t oil because it will burn cleaner, and I don't have to add as much Sea Foam. Still after all that I add 1/2 oz Sea Foam, and 1/2 oz Golden Spectro to EVERY gallon of fuel. Even though I run an injector wired wide open. 2T BRO! You will find from plug chops exactly what you need. Run the same mix thru several tanks w/ several plugs, and you will find what works best for you