• Powerful liquid-cooled 449cm3 4-stroke 4-valve Unicam engine is designed to produce power across a wide rpm band for easy-to-control operation.
  • Electric starter drives the clutch side of the crankshaft to provide superior lubrication of starter gears, and produce a narrow engine with a short, strong crankshaft.
  • Lightweight, compact, internal auto decompressor system provides superb cold starting and hot-starting operation.
  • Compact, lightweight engine assembly weighs only 32.2kg.
  • Unique Honda Unicam valve train provides both the light weight of a compact single-cam design and an optimum combustion chamber shape for maximum power engine rpm.
  • Unicam valve train features a single carburised camshaft directly actuating two 35mm titanium intake valves from above. The camshaft's centre exhaust lobe actuates two 30mm steel exhaust valves via a forked, low-friction, roller rocker-arm.
  • Lightweight titanium intake valves permit use of smaller valve springs, reducing overall engine height.
  • High-strength, low-carbon steel crankshaft with carburised main journals for maximum durability at sustained high-rpm operation.
  • ACG cover, clutch cover and cylinder head cover are made of magnesium to reduce engine weight.
  • Forged 12.5:1 compression slipper piston is lighter than conventional designs, for quick-revving response while maintaining excellent cylinder sealing and high-rpm power.
  • Double-carburised connecting rod utilises an updated big-end needle bearing and thrust washers for maximum high-rpm performance and durability.
  • Lightweight NiCaSil cylinder lining ensures cooler and quieter operation for extended engine life.
  • Press-fitted aluminium spark plug pipe fits between forked exhaust rocker arms, further contributing to compact cylinder head design.
  • 40mm Keihin FCR-type carburettor features four rollers on the flat slide, resulting in very light throttle effort, smooth operation, crisp throttle response and excellent rideability.
  • Carburettor features a throttle position sensor (TPS) that helps maintain linear throttle response throughout the rpm range.
  • Twin-sump lubrication system separates oil supply to crankshaft, piston and valve train from supply to clutch and transmission. This ensures a steady supply of cool oil to the clutch, eliminates clutch and transmission material contamination of the engine oil, reduces the amount of circulating oil and permits the use of a smaller oil pump.
  • Vertically split crankcases feature a built-in oil pump, reducing weight compared to conventional designs.
  • Exhaust system uses a lightweight stainless steel exhaust header and muffler equipped with spark arrester.
  • Dual radiators feature a refined core area for improved heat dissipation compared to conventional dual-radiator designs.
  • Coolant recovery tank is located underneath engine for improved mass centralisation. Coolant tank is protected by a plastic shield.
  • Gear-driven balancer reduces vibration and drives the water pump. Eight clutch plates provide the surface area necessary to handle the engine's massive torque, while carefully matched clutch springs provide a light feel at the lever.
  • New T-ring-sealed chain is approximately 1.6mm narrower, and stronger compared to conventional chains.
  • Durable 5-speed wide-ratio transmission.