13hp won't start

went to look at my SIL Huskee rider today.It has a 13hp Tecumesh.He says he cut grass with it last week but had to chock the heck out of to keep it running.Today it would crank and crank but no start.Took the plug out and there was spark but noticed it was bone dry.I sprayed a bit of starting fluid in the carb and got it to start but not keep running.The carb had gas at least to the bowl because I took it off.could something in the carb be plugged that's not allowing gas to get in?I could keep it running with a constant spry of starter fluid but thats it.if it's the carb where could I buy a replacement ? I sure would like to fix this problem and any help is much appreciated....russ