My Troybilt push mower has the above engine. It has started surging (I've also heard it called hunting) and then it will die. Very hard to get restarted. Any suggestions?

 

Surging can often be caused by a clogged or partially clogged jet in the carburetor. Disassemble and the give the carburetor a good cleaning. You can also look at the linkage from the governor to the carburetor to see if a linkage has gotten bent or a spring came unhooked though I think it's unlikely. My money is on the carburetor.