Before buying any parts borrow or buy a fuel pressure gauge,and check just before carb, also take the filter all the way off and blow backwards into a clear glass ( to see if there`s any water or other crap in system ) and see if that helps any..
If engine is warmed ,,hot,,engine off,, take off air cleaner if the blades are straight-ish up and down not shut then that is not the problem...While you got air cleaner off look down barrel of carb and pump throttle there should be a small stream of gas..use flashlight if needed..
Make sure while it`s running the gas level is real close to the mark on site glass on front of carb.( Hitachi carb ) . to high something might be in float needle ,,,,,to low starving for gas..The level doesn`t have to be exactly level with he mark just real close,,