Spark Plugs for 500s

There are many spark plug manufactures around and all have different codes for their spark plugs, please see below a list of the most common ones for standard fitment

500 original engine (479cc & 499cc):

Original plugs

Marelli CW 225 N or Marelli 6N; Champion L7 or Champion L 87 Y

Alternatives

NGK BP6HS or NGK BPR6HS; Bosch W7BC or Bosch WR7BC; Unipart GSP541

126 650cc engines

 Original plugs

Marelli CW 8 NP; Champion L81 Y

Alternatives

NGK BP7HS; Bosch W5BC