Motorcycle Repair: 1975 CB500T, starter solenoid, starter clutch

Question
Last winter, before putting my bike away, my 1975 CB500T ran on one cylinder and electric start worked great. I charged the battery properly over the winter. And replaced the spark plug on the left side. Now the electric start merely whirs (as in spins, but doesn't catch). The bike still kick starts, but while running, it usually only runs on one cylinder (even with the new plug). Fiddling with the plug wires can somewhat fix the issue, by creating a gap between the connection (i.e. the plug wire) and the spark plug, it will run somewhat smoothly. SO basically I pull it off and losen it so that it just barely touches. The starter appears ok, checked the carbs, and new plugs. Any reason why the electric start wouldn't work? Is it the battery? And is this why the plugs sometimes fail to fire? It is consistently the left side plug that will sometimes fail to fire. I'll be riding down the ride, and it will jerk back and forth, as the second cylinder goes on and off. Thanks for any help you could give.

nskaggs@pop3.utoledo.edu

Answer
Hi Nick,

There's several things to check; ignition system parts, wiring defects, loose or corroded connections, etc.. Review the files I sent to your email.

Electric starter:

Probalbly the battery not fully charged or defective cell. Could also be related to: starter solenoid defective or starter clutch defective.

Ignition problem:

Plug not firing is probably caused by ignition breaker points, ignition timing, ignition coil, defective plug wire or plug cap. You have to check all to find the problem.

Respectfully,
Mark Shively