No question this time but a report: I finally found some original Evinrude Engine Tuner spray and used it. It's amazing! The motor is running *much* quieter (83 dB(a) instead of almost 90 dB(a)) and smoother. I did use it by spraying it into the warm cylinders through the spark plug holes and letting it sit for an hour, though, not just blasting it through the air intake. One could really see how it dissolved all the carbon buildup. Even the spark plug hole threads became clean again.
Does anybody know any products that are still widely available and similar? The composition is markedly different from, for example, Sea-Foam.
Does anybody know any products that are still widely available and similar? The composition is markedly different from, for example, Sea-Foam.