no start...backfire

i have a 79 kz1000st shaft drive.rode it about 4 months ago and the motor was missing pretty good.went to ride it in the shed for winter storage and all it did was turn over awhile then backfire.nothind on the bike has been changed or altered. i cant seem to figure it out...some 1 help please

Hey, Something was different on the bike and you or I didn't do it,,,, mother nature did and had some help from Mr. Chemistry. Gas in the float bowls and the tank will go flat, gather condensation, which turns into water and sinks to the bottom of the tank. When it sinks to the bottom of the carb bowls, it is picked up by the main jets and sucked into the combustion chamber where it does nothing but wet the plug. Drain the bowls until Good gas comes out. Good, means New. Not the crap that was in there 4 months ago. When it starts and you get it in the shed, drain all the gas from the tank and the carb bowls. Joe