I have a Poulan Pro riding lawn mower. I had it sitting for over a year and it work great before storage. I took it out of storage and it tried to fire-up, but it wouldn't. So, I cleaned the carburetor, changed the plug, and replaced the battery.
A lawnmower mechanic showed me a little trick that has saved me many trips to the shop. He raised the "hood" on my mower and turned the engine by hand until it had passed the compression stroke, or top dead center. Just place your hands on either side of the screen and turn. If that doesn't work you might try removing the panel that covers the contact points and tap near them gently with something like a screwdriver handle. On my mower it was just below the steering wheel, near where my toes would be while mowing. Hope one of these will help.
