OS SPEED R21GT II 1DT00

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.

Tech specifications:

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.

Practical RPM range: 4,000 42,000 rpm

Max. power output: 2.65 ps / 2.61 hp / 34,000 rpm

Weight: 369Gr.