Sometimes don't start

[VetteVet]

Here is the picture:

http://i827.photobucket.com/albums/z...et/Starter.jpg

The tapered rubber bumper seals very well in the radiused cavity in the cap. At this point, I have to apologize. I did not modify the bumper as previously stated (senility is apparently starting to set in). I debated modifying the bumper or the cover and chose to modify the cover. I cut a very shallow groove in the metal cover (visible at 12 o'clock in the picture). This prevents a vacuum from forming in the cavity and preventing the main contact (copper disk) from engaging and directing battery voltage to the starter motor windings. This only occurs after running to temp AND after a short cooldown period. Immediate restarts or waiting a substantial period of time do not cause any starting problems. When a no-start occured, I noticed a slight, but noticable drop on my volt gauge (due to solenoid energizing), but not a large drop (indicative of the starter windings being energized). If these are your symptoms, then this may work for you. I had numerous no-starts prior to this mod, but with several months of use after the mod, I never once experienced another no-start.

Jep