I realize (and you mentioned) that sugar is not a well defined term, but calling degradation products of ethanol in gas “sugars” is still a bit of a stretch. Ethanol by itself usually forms some combination of acetaldehyde, acetic acid, 2-carbon peroxides, and CO2 (i.e. not sugars) upon autoxidation, though those species can react with other components of gasoline to form the precipitated “gum”. The structure of gum in the literature is pretty hand-wavy (high MW materials kinda just be like that sometimes) but tends to be much more more oxygen-deficient than conventional “sugars” (polysaccharides) even for ethanol blends and contains a wider variety of substructures. Though, I have seen some papers talking about certain microbes that can ferment the ethanol in gasoline, possibly via sugars, but I don’t think that’s the common degradarion pathway for a mower.
I realize (and you mentioned) that sugar is not a well defined term, but calling degradation products of ethanol in gas “sugars” is still a bit of a stretch. Ethanol by itself usually forms some combination of acetaldehyde, acetic acid, 2-carbon peroxides, and CO2 (i.e. not sugars) upon autoxidation, though those species can react with other components of gasoline to form the precipitated “gum”. The structure of gum in the literature is pretty hand-wavy (high MW materials kinda just be like that sometimes) but tends to be much more more oxygen-deficient than conventional “sugars” (polysaccharides) even for ethanol blends and contains a wider variety of substructures. Though, I have seen some papers talking about certain microbes that can ferment the ethanol in gasoline, possibly via sugars, but I don’t think that’s the common degradarion pathway for a mower.