If you’ve had the carb off, you may have reinstalled the gasket between the engine and carb incorrectly. There is a small hole in the engine block beneath the gasket and there is a corresponding hole in the gasket. Make sure the holes line up. You will also see the same hole in the carb. That passage port, or hole, is the pulse line for the fuel pump in the carb.
Also, check the ground wires.
LAD Specialties customer / tony kart / rotax / kt100