I had issues a few years ago until I started customizing my own mix. I start with the right amount of echo powerblend oil for 2.5 gallons of mix, add an ounce of marine stabil, and 2.5 ounces of seafoam. I run this in all my two strokes. I run seafoam and marine stabil monthly in my main mowers and every fillup on machines that run less than once a week.
More equipment then I know what to do with.