Description: 

The item will be released at the end of November 2025

This engine is a refined version of the previous model, developed in collaboration with our support driver and world-renowned Adam Drake.
The cylinder liner features a new 3-port design with revised port geometry. Additionally, modifying the crankshaft bore diameter has improved low-to-mid-range response.
The new outer head features a two-tone anodized finish, with the machined section anodized in blue—ADAM DRAKE's signature color—and incorporates a new laser design.
It has been reborn as the O.S. SPEED B21 ADAM DRAKE EDITION 4, offering an advantage on the race track.

Specifications
Displacement: 3.49 cc / 0.213 cu.in.
Bore: 16.4mm / 0.646 in.
Stroke: 16.55mm / 0.652 in.
Output: 2.65 ps / 2.61 hp / 34,000 r.p.m.
Operating RPM Range: 4,000-42,000 r.p.m.
Weight: 352g / 12.42 oz.

Standard Included Items
Glow plug O.S. SPEED T-P3 1 piece
Reducer 6,8
Exhaust seal ring 1 piece
Dust cap 3, 16, 18 1 each