Tough to troubleshoot from a distance but it could be the carb is getting gummed up from dirt/gasoline varnish which can block some of the very tiny holes/jets.
Do you use a filter between the tank and the engine? You should, installed in the hose between the tank and the engine. Some small engines have a tiny filter inside the engine housing, just ahead of the carburetor, but it is tiny. Maybe it is plugging. Change it as it can plug quite quickly.
If it is gum then an additive such as Startron or Seafoam may help since it does still run which means fuel is getting through the passages. If no fuel is getting through passages then they cannot help. Then tt may require a full carb. strip down and chemical cleaning but try the other things first.
Which fuel do you use? Do not use alcohol laden fuel or gasahol. It will create problems with small engines like this as they were never designed for it. Find a source of no alcohol fuel. If you have gas stations with 92 or 94 octane, no alcohol, premium fuel that would do a much better job.
Oddly some places like garden equipment sellers may offer a gas that has no alcohol, not sure what they use as a replacement, for chain saws, weed eaters, blowers, etc. It is not cheap but may be worth considering. Some areas you may be able to get Avgas.
If you cannot avoid use of gasahol then buy only what you need, midgrade or premium , not storing large quantities and use it up. IF it starts to get old, 4-6 months or less, then use it in the car where it will be well diluted and used quickly. Actually it's not good to buy large quantities of fuel that then sits for long times.
