I dont think that it would be a good idea to leave it stored for more than a month or so because the oil and gas suspension will seperate, and the additives in the oil could settle leaving a mess in the bottom of the tank for you to suck up it to the carb.
If it hasn't already been sitting for months, you can add some "stabilizer" to the fuel to extend its life. You can buy fuel stabilizer at any auto parts store.<br /><br />Cheers.
