Towards the end of a track day last week my starter motor stopped working. It was making a high pitched whirring sound but no engagement with the flywheel. Thought the drive gear might be a bit sticky and a tap on the side of the unit got it working until the next time it was needed! I have since done the following; 1. Earthed the block separately to make sure it is not a poor earth 2. Removed the starter motor, gave it a good clean (but it was not too dirty anyway!) 3. Tested it out of the car - it appears to work - drive gear shoots forward and spins 4. Put it back in, same problem! 5. Battery seems fine but hooked up to my tintop battery just to be sure. Same problem! I know of a local man who rebuilds starter motors, but wondered if there was any wisdom from within before I seek him out? I have been told that modern starter motors do not like being tapped on the side - it does not help and is more likely to break them? Thanks in advance. Garth