O.S. Speed 21XZ-B spec. III

Specifications:

• Displacement 3.49 cc/  0.213cu. in.
• Bore 16.27 mm / 0.641 in.
• Stroke 16.80 mm / 0.661 in.
• Practical RPM range 4,000 – 42,000 rpm
• Max. power output 2.65 ps / 2.61 hp / 34,000 rpm
• Scavenging port 3-port
• Exhaust port 3-port