Why is my chainsaw not starting?

I have a chainsaw my dad let me use. When I got it my dad had started it up and everything but when I get it home it acts like it doesnt wanna start. At first i thought it was probally flooded but it doesnt take this long for it tohave to crank. I bought a new spark plug this morning and it still wont crank. I know it will crank but its like something is keeping it from doing so. I was thinking maybe the gas is bad. I think my dad said it was sittin for a good moment.