I have bolen riding mower with briggs engine it will crank but will not start. It has a new battery and spark plug. From the gas tank to the carb. the fuel is flowing really good from but do not what is going on from there. When I try to crank it will give a pop every now and then. The mower has been sitting up for a year and it is only two years old. Possibly water was in gas when I put some new gas in. Could you help me with this problem. Also new gas has been added and still will not start.

there are small componets in the carburator that can get stuck when sitting a while, the gas while "crystalize" on these parts, but genearlly will start then immediately die (when floats stick)
to be sure about plug, remove plug, reattached wire, and ground outside(screw part of plug), generally by placing against metal on mower. try cranking, you should be able to see "spark" from plug. (test to make sure wire is good too)