In my 2nd season of light tree falling and sawing firewood, I've seen my chainsaw already fail. It would start but would not power up consistently making me think I needed to clean the air filter or check the fuel filter. Air cleaner element was fine, but when I checked the fuel filter, it wasn't attached to anything and several pieces of fuel line was laying in the fuel tank looking like dried up pieces of macaroni. I suspect your fuel lines are not very fond of the ethanol which may be in fuel often sold.
Personally, I use 93 octane marina fuel without ethanol for this reason, but my fuel lines failed anyway. I suspect this is out of warranty and the local servicing dealer indicated it would cost the same amount as a new Poulan chainsaw....then suggested I buy a Stihl chainsaw. Is this how you prefer to see your business evaporate?