Motorcycle Repair: starter solenoid, starter solenoid, starter button

Question
QUESTION: Just how does the starter solenoid work?  I push the starter button, starter dog engages, but starter does not engage.  Short across battery terminal and starter terminal on solenoid and starter turns dog backwards.  Have tried two different solenoids and get the same results.  Just how is the solenoid supposed to function in relation to the starter shifter fork?

ANSWER: What year and model?
Mike

---------- FOLLOW-UP ----------

QUESTION: 1984 Harley Davidson FXSB LowRider.  Also discovered starter is turning dog in right direction.

Answer
A solenoid is nothing but a magnet. When you hit the starter button it sends 12 volts to a post on the solenoid. One of the other posts are hot with 12 volts. When you hot the starter buttton it engerizes the magnet and it slides, completing the circut to the other post and sending 12 volts to the starter.
Good luck and happy riding
Mike