Thanks Ken, it would help if we can verify that it is a tank-under-carburetor type. The picture should show that. Also, you could remove the air cleaner and trickle a small amount of fuel into the carburetor air intake while it's running. (stand clear of the carburetor in case of spits). If it keeps running, we will know for sure that the problem is fuel starvation. Once we are at that point, replacing the fuel pump diaphragm (between the carburetor and the fuel tank) and blowing through the various fuel passages in the carburetor are the main steps to take. Best to do the fuel-trickling trick before you buy the new fuel pump diaphragm, because if it isn't fuel starvation you'd be wasting your money.
