I have a 4Y Engine. One day, it just wouldn't start. When I try, all I hear is a "Clacking" noise from the starter. I checked the Fly Wheel, all the gear teeth looks good. Tested the starter, the Pinion Gear shoots out and turn. I also went to file the pinion gear, so the pinion will engage into the flywheel easier. I also, went out to buyer a new starter. Still the "Clacking" noise. I never had a problem I couldn't solve, but this one is just driving me crazy.