Just had similar situation with my 09 Leopard. It would crank fine but would not fire. when I used external starter, it would crank and fire up and run just fine. Systematically I replaced all electrical components (stator, box, key switch, battery, checked all grounds, plug, starter relay, wiring harness (those pesky broken pins), and it still did the same. Spin but not fire from the key. Finally I replaced the coil and it fired right up. It appears the coil was weak. The remote starter spun the engine fast enough for the stator to put out enough volts to fire the coil, however under key start conditions, where it uses the battery to provide the volts to fire the coil, there was insufficient voltage for the weak coil to properly operate.