To check the sprocket nut for the engine, remove the shifter lever (1 bolt),foot peg assembly on the left side of the engine (4 bolts), the cover for the starter motor(2 bolts) and then the sprocket cover(4 bolts). Some models use phillips head fasteners, others socket head cap screws(Allen type).
The instrument lighting problem may be due to either a blown fuse or corrosion in the fuse clips. Look under the seat around the battery for the fuse holders, some bike's have them with a transparent cover, others are in a black holder.
If the fuses are bad the replacements are the AGX size available at auto parts stores.Probably 10 or 20 amp ratings.
1982 GPZ1100 B2
General Dynamics/Convair 1983-1993
GLCM BGM-109 Tomahawk, AGM-129A Advanced Cruise Missile (ACM)
