The picture shows everything you need to do a top end rebuild on your MC21/28. One kit includes all parts for one cylinder (cylinder ‘A’). To overhaul both cylinders please order 2 kits.
Cylinder A = 54.008mm – 54.011mm use Piston B = 53.966mm – 53.969mm
Cylinder B = 54.004mm – 54.008mm use Piston # = 53.962mm – 53.965mm
Cylinder C = 54.000mm – 54.004mm use Piston D = 53.958mm – 53.961mm
Piston to bore clearance = 0.039mm – 0.045mm