Chain saw emitted sparks and now does not start.

Question

chain saw has only been used for about 10 hours before it died. chain saw worked on saturday...new unleaded gas was used and used the correct gas/oil mix. Sunday the saw took a while to start, used same gas/oil mix from saturday. Was able to start the saw a few times but the saw would only run for a few minutes and die. Eventually it did not start at all.

On saturday i used the saw several times until the gas ran out and refilled and restarted. Just talked to someone who said you cannot let the saw run until it ran out of gas or you'll destroy the engine. I did see sparks on either saturday or sunday (I don't recall which day). I kept the saw full of chain oil.