I am in process of swapping out my 2003 sportsman 600 engine with another used motor of same year. Problem I am having is wiring off magneto is different. Wiring plug doesnt match ignition coil that I have. Old motor was made before February, 2003. New one made after February, 2003. Tried changing magneto and flywheel from old one, will fire but not running right....any ideas?