crank trigger, pick-up points

[jefferygs500]

what is this guys where is it locate? and what are the causes if this is bad??? How do i check to see if it is bad? thanks.

[scratch]

It is a metal plate that rotates past two electrical pick-ups that send the signal/electircal current to the coils to fire the sparkplugs; one for each plug.  They are located under the small, round cover, held with three bolts on the right side crankcase.