Sea Foam works well and I put 1 ounce of it when I get gas for mowers in a 4 gallon container. I also add 1 ounce of Stabil and 1 ounce of Marvel Mystery OIl. I live in WI which has had ethanol in its fuel since the early 1980s and since I started doing so in the mid 1980s have had no fuel related carburetor problems. Do nothing else to keep the fuel fresh. I have 3 mini bikes, 20+ push lawn mowers, about 10 garden tractors, 2 weedeaters, 2 chain saws, 2 gas powered air compressors and a gas powered hedge trimer. I also use that same container to mix the gas for the 2 strokes. I have been using synthetic OPTI 2 oil mix also since the 1980s. One pouch per gallon and runs all mixs fron 16 to 1 to 100 to 1. Now that I solved all that I have time to worry about other things. Roger
PS I forgot I have 3 tillers and a portable generator all of them use treated fuel. Roger