My experience with Magnum engines is the low end is usually set to lean from the factory. Taking a small screw driver, gently screw the low end adjust in (lean) to find out where you are. If you get less then a couple of turns, you must keep easing the adjustment out (rich) a quarter turn each time until you get running. Additionally, have your blown into your fuel lines to ensure that all is well. I blow into the vent (muffler) line and remove the fuel (carb) line. Naturally when blowing, fuel should come out the carb line. If not, start all over with your fuel tank.

Would appreciate to know how you eventually solved problem.

Ted in Las Vegas