Motor starts and runs for 10-15 seconds and then dies. Noticed lot of gas around air filter. Had carb rebuilt and still same problem.?

You probably have crud in the gas tank, lines or filter. Rust will do it every time. You may have to inspect the fuel system and take the carb apart and at a minimum clean the fuel valve.

The entire fuel system should be cleaned when you find any type of debris within the carb bowl.

Didn't find anything in fuel system. Rebuilt carb seems to be OK.