The neighbors moved and left behind a troy bilt lawnmower. They only used it once and then it was left out in the weather over the winter. I changed the gas and took the carb off. It was full of water, so I shook as much water out of it as I could. Then sprayed carb cleaner in it to dry it out. If I spray engine starter in the carb the mower will start, but doesn't stay running. What can be wrong with it. The float moves freely.

Sound like fuel is not getting to carb. Check fuel line to make sure its not pinched or broke and that it is connected at the tank.Take the fuel cap off as se if that make a difference