What is the job of a solenoid? How does it work?

please email me at:

 

It's a switch that sends power to the starter.

How does it work? Pretty well, until they get old, then you have to kick
them once in a while.

 

google is your friend (search on 'solenoid'):
<http://www.detroitcoil.com/whatis.htm>

To be more specific about the most common vehicular application (search
on 'starter solenoid definition):
<http://www.aerac.com/Newsletters/2000/Complete_Circuit.htm>

From this page, the relevant extract is:
"A starter solenoid that is used in automotive applications must
accomplish these TWO functions and in this order:
1) Work as a solenoid, which by definition, is a device operated by
electrical energy to accomplish a mechanical motion, i.e. pulling the
starter drive into the flywheel.
2) After the above function is done and the drive is engaged into the
flywheel, the solenoid should work as a high output relay and apply the
battery power to the starter motor."
For motorcycles, replace 'flywheel' above with 'ring gear on the clutch
hub'.

Other solenoids are used in automobiles to actuate power door locks,
power trunk latches, and so on.

 

Nobody has done it like that for years.

Newer bikes tend to use an overrunning clutch with the starter motor
constantly engaged.

Most cars and some motorcycles (air cooled H-D, BMW twins, M-G) use
a solenoid to engage the starter drive.