Re: Ethanol killing small engines
best thing you can do is shut the petcock a few minutes before you want the engine to shut off. I essentially run all the fuel out of the carb before I shut the engine off. that way the ethanol doesn't juts sit in the carb. if I know I'm not going to ride a bike for a while, I run all of the fuel out of tank so that it doesn't get stale. 3 weeks is about as long as I let any gas sit... mixed or not.
I know exactly when to shut the petcock on my way home to coast into the driveway... with an empty carb.
I haven't had any problems yet with any of my small engines.