What engine? Model number of Briggs example(###) ###-####B! Remove the spark plug and with it grounded to the metal of the engine. crank and look for spark. No spark, try another spark plug. If it has spark, put a teaspoon of fuel direct into the spark plug hole, re-install the spark plug ad see if the engine starts for a few seconds. If it does, the fuel to the carburetor needs to be checked, then the carburetor float bowl needs to be removed nd the float and needle check,to be sure it is not stuck, and fuel is entering the float bowl.