Must be the gas. You left any gas in during storage? If so, you have any Stabil in? If not, most likely it's you gas.
Since you can start it, dump the old stuff out. Get a can of SeaFoam. Mix 2 oz per gallon and run a tankful through. As long as you can start the engine and run it, I doubt you have to bring it in. Dealer don't cover stale gas everytime even under warranty.
I don't think you have exhaust blocking because it's too new and only 2 hours. Do the SeaFoam, people swear by it.