[chris vickery]

One of the main issue with ethanol is that it is hygroscopic in nature, which means it has a propensity to attract and hold water. This is the reason that it is useful as a fuel line anti-freeze. Water in the fuel is one issue as water attacks and corrodes the fuel system from the inside out- gas lines, fuel tanks etc. All of thee fine rust particles clog up the system, filters, carbs, pumps etc.
The ethanol as mentioned earlier is also a solvent when in contact with rubber components, plastics etc. Once again, turning these into goo which wreaks havoc on the fuel system.
A friend of mine had a small engine shop that he recently sold when he retired. He always told me that the best thing ever to happen for him was when the Petroleum companies started adding ethanol to the fuel.
His staff was always super busy, especially in the spring time when all the lawn and garden equipment came out of storage and then would not start. He kept plenty of kits, carbs and fuel pumps on hand to deal with the problem.
It seems that this industry has been slow to adapt, or outright refuses to upgrade their products to comply with modern fuels. Why would they?
The auto industry has adapted and overcome by introducing modern materials which are resilient to ethanol and other additives. Many cars are actually designed now to run on blends. South American manufacturers are building cars to run on as much as 85% ethanol, derived from corn.
I think in the long term, it is a case of using the best product available at the pump if it can be found. Otherwise, I would suggest that in the future, rebuilds on HMVs will require the ue of modern components in the overhaul of the vehicle. A 30 year old rebuild kit for your carb is still a 30 year old kit, made of rubber. Only modern materials made to handle ethanol will work long term.