I have the same problem you do and I run E0 only in my power equipment.I have started using 100LL AVGAS in my 2 stroke equipment all the time and use it to flush out my mowers and 4wheelers when they are put away for the winter.The guy at the airport claims it's good for 10 years but I take that with a grain of salt.Even the pump E0 is only lasting 3-4 months before going stale in my experience.I tried Stabil ,Seafoam,Marvel ,etc with no luck.I did have some saw gas to last thru the winter with echo oil in it,had a can of straight gas beside it .The straight gas was stale ,both were bought at the same time.After seeing that ,I began using a 2.6 oz of 50:1 oil in 5 gal of gas all the time during season then flush in winter with the 100LL.I would expect racing fuel would last as long as AVGAS.It is about $3 per gal higher than AVGAS here.