If you used old gas in a lawn mower, should I add Sea Foam? [SOLVED]

Thanks for the question, Bob.

Sea Foam will clean any residues and varnish from the old fuel. It’s best practice to drain any old fuel (or run it to use it up), and then add 16 oz of fresh gas with 8 oz of Sea Foam (or whatever amount of fuel you’d like with a 2:1 ratio). That will create a strong cleaning concentration and work very well to clean up the entire fuel system. After that, add 1 ounce of Sea Foam per gallon of fuel to prevent it from degrading when it’s sitting.