Lets start with a little background. When you got the motor, did it have a key start or was that something you added? Did you do the engine work or was it done by a kart shop? I’ll assume that you have the Leopard Overhaul manual plus the Assembly Instructions and User Manual.
Check the needle valves in the carb are properly set and that the butterfly is completely closed.
It’s not uncommon to have an ignition failure on a Leopard. As a new comer, it might be wise to have a kart shop diagnose and repair your engine. Could also be cheaper going that route and will be less frustrating.
LAD Specialties customer / tony kart / rotax / kt100