"Overhaul" meaning that the entire carburetor was disassembled, cleaned in solvent, adjusted and reassembled with new gaskets?
And now the engine doesn't start.
A carburetor overhaul kit includes with its various gaskets a float gauge that's used to adjust the float's level which, in turn controls how much fuel enters the carburetor. Did someone in fact adjust the float's level?
If you or the man who "overhauled" the carburetor doesn't know about the float level and its correct adjustment then I suggest you remove this carburetor and send it to a shop that overhauls carburetors professionally and have them do a proper overhaul on your carburetor so that the engine will start when cold and run with good power and fuel economy. Otherwise you're simply wasting your time and money.