Starter Gear

[Sven]

No, this is not a question about a loose nut.  There are plenty of loose nuts on this board already.

In recently replacing the gasket on my starter gear cover (and I was not pleased that the cover is what holds one of the small gears in place...it all but fell out when the cover was removed), I started wondering:

What does the starter gear do?  I presume its involved in starting the motor.  How does it do that?  Does it do anything once the motor is running...or does it just sit once everything else is moving?

PS:  NHL starts tomorrow...GAME ON!

[Maniac]

The starter is a small electric motor that, when activated, spins the engine. The little gear on the starter is spring-loaded, when the motor turns on the gear pops out and engages a larger gear on the engine, when the starter motor is turned off the gear retracts and the two disengage.

When the engine is running, the Starter doesn't really do anything.

[Sven]

Well, that was clear, thanks, M.  I wish I had known that before I put the cover back on, I would have poked around a little more to see how everything relates...but then I probably would have screwed something else up!
 

[ray nielsen]

The starter gear serves as a gear ratio modifier, allowing a small electric motor to turn over a larger gasoline engine.  

The gear is ALWAYS in mesh with the starter clutch, and that's where the catch/release mechanism is located.  

The starter clutch is essentially an overrunning clutch mechanism that allows the starter to rotate the engine until the engine speed is greater than the starter motor, then it releases and disconnects the starter motor from the engine.  It is located inside the engine because it need lubrication oil to function.

On a car the engagement is accomplished by moving a gear into engagement with a "ring" gear around the engine's flywheel when starting, which produces the distinct "clunk" sound when starting a car.