I started this engine up about 3 weeks ago and it was fine but now for some reason it will only stay running as long as I have the key turned to the on position and the starter is going. The second I let go of the key the engine dies. It's getting pleanty of spark. The only weird thing is I've lost power to the control box to shift into neutral, so I added 12v to the green wire and it shift's fine but it still won't stay running. I tested the continuity on the purple wire all the way to the back and it's ok, but it's not producing any power. It goes to this little circular casing with, one power wire in attached to a small circular contact, and the purple wire attached to another contact with a cap over them both. Could it be that, or a dirty carb, or is there a way to test the points? Please I need help this is driving me crazy! any suggestions will help. thank you guys so much.