Motorcycle Repair: ELECTRICAL PROBLEMS, starter solenoid, clutch lever

Question
I have a 1981 Honda Cm400C That keeps shorting out the starter solenoid. I will buy a new one put it on and it will start and run fine. but when I let the bike set in the garage a few days and go back to start it the only way it will start is to jump the solenoid. could I have a short or some bad relays?  

Answer
Tracey, First go here: http://oldmanhonda.com/MC/WiringDiagrams/MCwiring.php#class
Find your wiring diagram, print it out and highlight the starter solenoid circuits for reference.
For the electric starter to function the bike has to be in neutral and/or the clutch lever must be pulled in. There is also a diode in the circuit (called rectifier). If there are interruptions in the circuit, the starter won't activate.
Highly likely is the clutch lever switch, which has a little plunger on the end, activated by the lever itself. Look at the lever bracket and check where the small 2 wire connector goes into the assembly. Pull the clutch lever in and look for the little plastic tip of the switch. If it is missing, then you need to replace the switch and harness. You will have to loosen the cable slack with the cable adjusters, then remove the lever pivot bolt and the lever. Find where the wire harness is attached, disconnect it from the main harness, push the switch assembly through the lever bracket to remove. Reverse the instructions to reinstall a new switch. Make sure your neutral light is working as it may be a path for the circuit through the neutral switch off the transmission. If all that is okay, get an ohm meter and check the diode for only passing voltage one direction.
What you haven't mentioned is the condition of your battery and charging system. Batteries get old after a couple of years and loose their charge when they sit for awhile.
The ignition system is not battery powered, so you can bump start the bike and it will light up and run. When it is running check the charging system and battery voltage to be sure you don't have other problems. On a bike this old, it is a good idea to strip off the bodywork and inspect all the wiring connectors for clean terminal connections, including the ground leads.

Bill Silver