Non-ethanol gas locations.

[3-D Video]

I haven't found anything but anecdotal evidence to confirm the gumming of carburetors, nothing that suggest the chemistry of what appears to be happening. "Appears to be happening" because there's a lot of evidence out there. And, a lot of Agri-bi$$ lobbying for their corner of the ethanol market.

You may find the following interesting:

“The resin released by ethanol makes its way through the fuel system where it sticks to valves and other internal engine parts.Â* The buildup of this sticky black substance has bent pushrods, clogged intake valves and ruined some engines.Â* Affected engines may run rough, stall or bog down under load.â€� Â*Â* Boat U.S. MagazineÂ* July 2006 Â*

“Employees at the shop regularly rebuilt carburetors gummed up from the so-called “varnishâ€� that builds up from unstabilized gas left sitting in engines.Â* But since ethanol started being added to fuel sold in Florida in 2007, the power-equipment pros were seeing something new:Â* metal parts crusted up, plastic parts stiffened and cracked, and everything rubber, including the tips of needle valves, deteriorated.â€� Consumer Reports.orgÂ*Â* June 24, 2009
http://blogs.consumerreports.org/home/2 ... gines.html

“Examples of reported damage, determined to be caused by E10 fuel. Â*

Ethanol Gasoline – General Problems/Issues:
Phase separation (P/S) of gasoline.
Water contamination (W/C) of gasoline.
Attract, absorb and hold moisture in fuel tank.
Increased occurrence of lean, water-diluted fuel.
Vapor lock or fuel starvation.
Drop in octane (after water absorption, P/S and W/C occurs).
Decreased fuel efficiency and mpg.
Decreased life cycle of parts and engine.
Decreased shelf life of gasoline.

Parts Damage:
Wear and damage of internal engine parts.
Damage to metal, rubber, and plastic parts of fuel system.
Corrosion of metal parts in fuel system and engine.
Deterioration of elastomers and plastic parts.
Deterioration of non-metallic materials.
Fuel permeation through flexible fuel lines.
Drying, softening, stretching and/or cracking or rubber hoses, seals and other rubber components.
Oxygen sensor damage.
Damage or premature disintegration of fuel pump.
Carburetor damage, including clogging.
Dirty and clogged fuel filters.
Clogging and plugging of fuel injectors.
Destruction of certain fiberglass fuel tanks.
Removal or fading of paint and varnish (both internal and external parts of engine).
Piston/bore failure through knock/pre-ignition.
Piston ring sticking.
Unsuitable ignition timing resulting in ignition failure.
Gumming-up of fuel injectors, carburetors, etc. due to release of accumulated deposits in engine from ethanol alcohol’s solvent properties.
Â*
E10 Drivability Issues:
Engine performance problems. (Lack of power/energy).
Hard starting and operating difficulty.
Hesitation and lack of acceleration.
Stalling, especially at low speeds.� November 2009 www.Fuel-testers.com