How can i fix my yamaha blaster 1992 headlight?

when i bought the fourwheeler the headlight has always been dull it has never been bright it is always just very dim no matter how i rev it i changed the lighting coil but that didnt help. What can i do to fix this problem?How can i fix my yamaha blaster 1992 headlight?Would try a new bulb and cleaning the reflector.