chunks of stuff in the side cover 98 fe600s

Still fairly new to motorcycles, While in the process of repairing my 98 fe 600s throttle cable blown off carb and vacuum lines falling off, realized there was excessive rattling from the right side of the engine on higher rpms, removed black plastic side cover. three bolts there was some magnetic looking stuff laying below drum, Not really sure what the drum is thinking maybe lighing magneto? then got playing around with it and when the engine turns over what ever the drum is grinds and smacks the wiring harness coming out of it. Is this ignition or lights only. I kick start only my bike so not sure if charging system works at all or not? This bike sat for over 6 years i bought it this year, threw some oil in it and have put 7 rides and around 150 miles and no problems yet. well other than the whole cable and carb blowing off thing. The Questions i Guess whats hidden under the black plastic cover on right side and whats likely the cause of the peices and do i HAVE to fix it, and What should i do to make this engine more reliable? should i adjust valves rings? do nothing till it breaks