OS Speed R21 GT II is an all-new 5-port engine.
It features a newly developed underhead, cooling-head, crankshaft, Specially made to fit on-road GT track.
The OS Speed R21 GT has a 7mm carburetor restrictor.
Features:
- The crankshaft uses two tungsten counterweights. We have optimized the mass balance by reviewing the detailed dimensions.
- The inner head has been revised. Improved low and medium speed feeling and idling performance. An O-ring is also used to reduce vibration and improve dust resistance.
- The weight of the new outer head, compared to previous model has been reduced. Fins of outer head has been machined.
- Equipped with 5 scavenging ports and 3 exhaust ports to meet IFMAR regulations.
- Equipped with a double-adjust type 22E(B) GT carburetor. The new venturi is 7.0mm(RED) AL2.
Specifications:
RPM Range | 4.000 – 42.000 rpm |
Max. Power Output | 2.65 ps / 2.61 hp / 34,000 rpm |
Weight | 369g |