For parts or repair...Bad source coil... Used Stator Assembly from a 1985 Yamaha SRV540...Lighting coils and pulsar coil tested good but Source Coil is bad (see picture # 3) one wire missing a connector  ... missing 1 screw.... 5 wires...Black with male end, Yellow (its dirty in the picture so it looks light brown), Yellow with black stripe, White with red stripe and Brown      ...... Check part numbers before you buy..but according to Yamaha Fiche it should fit 1985,1986,1987,1988,1989, 1990, 1991 SRV540        Please check pictures and part numbers to see if it matches