Starter motor 'disengaging ' too quickly.

[rknowles]

I have a '66 Bug w/1300 motor, converted to 12V by PO, runs fine, but starting can be a problem. When I turn the key, the starter engages with the flywheel for only about 1/8 of a second, turning the engine over maybe one revolution, before it disengages from the flywheel & spins freely. This is fine if the engine starts right away (and most times it does), but it can take 10-15 turns of the key to get it going when it's been standing a while. The starter motor turns strong, but it's only connected to the flywheel for an instant when you turn the key, so it won't crank the engine for more than about 1/4 of a second at most. Any ideas before I put my baby up on the stands & start pulling things off? Loose mounting bolt? Dodgy pinion gear? Worn/broken bushing? Mice in the transmission casing?

[Digger89L]

I would check the battery's output first, then starter solenoid. It could be a mechanical fault with the internal operation of the solenoid (broken or weak return spring, for example) or it could be that it is not getting enough DC power to keep it engaged. There's a quick tutorial here: http://www.wikihow.com/Test-a-Starter-Solenoid on how to test the solenoid.

[planenut]

I believe you'll find the "bendix" in the starter is bad.

[Blue Baron]

When the car was converted to 12 volts, did that include the starter motor? 6-volt starters can quickly destroy a flywheel ring gear when running on 12 volts, and the disengaging of the starter could indicate lack of contact due to a chewed up ring gear.