just got my Carb rebuilt. Installed it and it started right up... after about 15 seconds (idles fine) i started smelling a weird smell and smoke started coming from around where the exhaust hits the engine. Is this normal or did i possibly screw up one of the connections? It did not smell like exhaust, should i run it and let it burn off or will i mess something up. A Side from the Gas connections how important are the other ones to get correct?