BSA M21 Piston +40
B165/040. 12659.040. 66-1217. 70-8157with gudgeon pin and rings
040=83 mm
Replica
Compression height: 31 mm
Piston Clearance 0.12mm or 45thou
with gudgeon pin and rings
040=83 mm
Replica
Compression height: 31 mm
Piston Clearance 0.12mm or 45thou