Hello, you are in the same boat I was, but I bet you will all get it sorted, anyways, to fix this issue try these steps:
1) Make sure your finger is totally covering the exhaust
2)Try detaching the fuel line that goes to the exhaust pipe and BLOWING down it until fuel moves
3)Check for holes in the fuel line and that they bare all properly attached
NOW I BET YOU IT WILL BE THIS:
CHECK WHETHER THE FUEL TANK HAS AIR LEAKS, IF A HISSING SOUND CAN BE HEARD TRY RE-JIGGING THE TANK LID AND HOLD DOWN, I bet this will fix it.
Prime the engine with fuel by putting your finger over the exhaust or air intake and then pulling the starter until you see the fuel reach the engine. Once you see the fuel reach the engine pull the starter another couple of times to spread fuel through the engine. If it will not prime make sure all the screws around the engine and manifold are tight and that the lid on the fuel tank is closed. If it still will not prime take the end of the fuel line that connects to the exhaust off and blow down it which should force fuel into the engine.