Sea Foam... a gasoline stabilizer. 16 oz. $10.99 at WM

http://www.westmarine.com/buy/pennzoil--sea-foam-fuel-stabilizer--13836119

The same stuff, and quantity at Walmart... (from BIC warehouse) $21.16

http://www.walmart.com/ip/16664932?www=true&productRedirect=true#ProductDetail

I guess someone told Walmart it had a marine application... but WM apparently thinks it is for lawnmowers. GRIN

The guy down the dock swears by it.