OS OSSP B21 Adam Drake Edition 4

The OS Engines O.S. SPEED B21 Adam Drake Edition 4 (part number SCH-OS1FH00) is the latest collaboration with world‑famous O.S. team driver Adam Drake. Built to his specification, this edition features a redesigned cylinder liner, crankshaft and outer head to deliver better balance, more torque and increased power for enhanced driving performance.

With a compact 3.49 cc displacement and an output of 2.65 ps (2.61 hp) at 34,000 rpm, the B21 Adam Drake 4 offers a broad practical operating range from 4,000 to 42,000 rpm. Weighing just 352 g, it combines strong performance figures with refined response characteristics shaped by Adam Drake’s input.

Performance Enhancements

• Redesigned cylinder liner for improved balance and response
• Reworked crankshaft to increase torque and power delivery
• Updated outer head to complement the new internal geometry

Key Specifications

• Displacement: 3.49 cc / 0.213 cu.in.
• Bore: 16.4 mm / 0.646 in.
• Stroke: 16.55 mm / 0.652 in.
• Output: 2.65 ps / 2.61 hp @ 34,000 rpm
• Practical RPM range: 4,000–42,000 rpm
• Engine weight: 352 g / 12.42 oz

Standard Accessories

• O.S. SPEED P3 glow plug
• Reducer 6II (blue) AL2
• Reducer 8 mm (blue) AL
• Exhaust seal ring
• Dust cap set: 3 mm / 16 mm / 18 mm