Motorcycle Repair: !977 FLH Shovelhead, solenoid starter, starter button


Question
When I depress Starter button I hear my new relay "click" and i hear Unknown age Solenoid  " click" and I hear the Starter turning but not engaging.
Volt readings are --at Solenoid  battery terminal "long post" reads  12+V. and once I push Starter button it goes down to the 10V.
Solenoid Starter terminal "short post" is 10v as the start button is pushed.
10 volts is also read on the starter itself at its connection from Solenoid  as the the starter is heard winding but not engageing.

new battery, fully charged  

I watched the previous owner use a screwdriver at the solenoid and the solenoid would really spark and the motorcycle would start!!! It was quite a "light show" to see him do this! Im guessing he destroyed the solenoid and this is why Im having problems.

Ive also noticed that when i use the kick start and  kick it a couple of times over and then i try the electric start , the electric start "sometimes"  will work  for a few turns!!!

My guess is i need a new Battery ground wire (it looks wore out), new Battery to Solenoid cable (It looks poor), Solenoid to Starter cable and a new Solenoid. What do you think?    thankyou for reading,  Dave in Seattle:)

Answer
I would go ahead and replace the wires youa re refering to, since they look old and bad. If the starter still isnt working, then replace the solenoid and relay. What is happening is the voltage is being dragged down by the above items and your not getting enough voltage to the starter.
Good luck and happy riding
Mike