OS SPEED R21 GT is an all-new 5-port engine.
It features a newly developed piston and 5-port cylinder, crankshaft, crankcase, Specially made to fit on-road GT track.
The OS SPEED R21 GT has a 7mm carburetor restrictor.
- Displacement: 3.49 cc
- Bore: 16.08mm
- Stroke: 17.20mm
- Intake ports: 5-port
- Exhaust port: 3-port
- Practical RPM range: 4,000 – 42,000 rpm
- Max. power output: 2.65 ps / 2.61 hp / 34,000 rpm
- Weight: 369Gr.