While not an avid ethanol proponent, it can be worked with - which is good as we don't seem to have much choice lol
Lower concentrations of ethanol in our fuel (like E10) has only two problematic effects relevant to our use, both of which are pretty straightforward - the deterioration of elastomers (rubber-like parts) like seals and other components & phase separation. Ethanol is also a solvent, so filters should be examined regularly for debris. While your fuel tanks may be clean, it's unlikely the station's are and contamination is common.
Unlike modern outboards, our kits have few rubber/plastic components exposed to fuel, the only one of consequence is ofc the fuel line itself, easily replaced when needed. While the floats are plastic, they seem to be quite alcohol resistant and haven't proved a problem. Unlined fiberglass fuel tank deterioration is one of the problems experienced by boaters for example, in time the dissolved residue makes a horrid mess of the entire fuel system.
Phase separation can be far more problematic in our application, particularly with the two strokes & is another reason why boaters seem to have been experiencing greater difficulty. Water & alcohol mix quite easily whereas water and gasoline/oil does not, if enough water is introduced into the fuel (condensation & even ambient humidity) the water is drawn into the ethanol and the mixture will separate from the gasoline, forming a layer at the bottom of the tank. This water & ethanol blend will displace the oil & fuel mix as it's heavier, causing both a lack of lubrication as well as ignition difficulties as it's introduced into the engine.
As a result, care should be used to reduce the introduction of any water into the fuel by using clean, nonvented containers (typical gas can) stored in a stable temperature, preferably indoors & out of direct sunlight. If your MB is going to be sitting for any longer than a month, the fuel should be drained completely as the "shelf life" of an ethanol blend is only about 2-4 weeks, depending on storage & exposure.
Given our reduced consumption rates and shelf life of ethanol, no more than two gallons of fuel should be purchased at a time - or whatever you would normally use in a month.
While the effectiveness of ethanol as a fuel additive to reduce our petroleum consumption is highly controversial, it's introduction is widespread & inevitable. To my knowledge not all fuel stations are required to label their pumps with the given amount of ethanol (private tanks like marinas for example), so unless it's advertised specifically as "alcohol free" you should assume it has some ethanol content. The actual ethanol content can also vary wildly from what it's been labeled as in any case. Yet with a few easy precautions ethanol blend fuels can be used effectively in our simplistic fuel systems without adverse effect.
