This is the Piston and Cylinder Assembly for the O.S. 12XZ Engine (OSMG2051) FEATURES: ABC cylinder liner construction, "A"luminum piston with "B"rass liner that is "C"hrome plated, Non-ringed, three intake ports for smoother acceleration INCLUDES: One Piston, One Sleeve REQUIRES: Assembly into engine. Line up the notch on sleeve with pin on crankcase. SPECS: Total cylinder sleeve length: 31.2mm (1.23") Bore: 16.3mm (0.6") Total ports: 4
