• Powerful four-stroke 450cc liquid-cooled four-valve Unicam engine is based on the award-winning CRF450R and CRF450X engines.
  • Compact, lightweight engine designed specifically for ATV usage is worthy of its CRF heritage.
  • Unicam valve train provides the light weight of a compact single-cam drive and the optimum combustion chamber shape for maximum power at all engine rpm.
  • Unicam valve train features a carburised single camshaft that directly actuates two 36mm titanium intake valves. The camshaft exhaust lobe actuates two 30mm steel exhaust valves via a forked, low-friction roller rocker-arm.
  • The TRX450ER features an electric starter that 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 provides superb cold-starting and hot-starting operation.
  • Kickstart version incorporates ATV-type forward kickstarting for ease of starting and light weight.
  • Crankshaft is made of high-strength, low-carbon steel with carburized main journals for maximum durability at sustained high-rpm operation.
  • Cylinder head cover is made of magnesium to reduce engine weight.
  • Forged three ring 12.0:1 compression slipper piston is lighter than a conventional design, revving quickly while maintaining excellent cylinder sealing and high-rpm power.
  • Double-carburised connecting rod utilizes a big-end needle bearing for maximum high-rpm performance and durability.
  • Nikasil cylinder lining is lightweight and provides cooler and quieter operation for extended engine life.
  • Press-fitted steel spark plug pipe fits between forked exhaust rocker arms, further contributing to compact cylinder head design.
  • 40mm Keihin FCR-type carburetor features four rollers on the flat slide, resulting in very light throttle effort, smooth operation, crisp throttle response and excellent rideability.
  • Carburetor features a throttle position sensor (TPS) that helps maintain linear response throughout the rpm range.
  • Twin-sump lubrication system separates the oil supply for the crankshaft, piston and valve train from the clutch and transmission. This ensures a cool supply of oil to the clutch, eliminates clutch and transmission material contamination to the engine oil, and reduces the amount of circulating oil and the required size of the oil pump.
  • Vertically split crankcases feature a built-in oil pump, reducing weight compared to a conventional design.
  • Left side countershaft bearing and axle carrier feature double-row bearings for added durability.
  • Exhaust system uses a lightweight stainless steel header and muffler.
  • Radiator is lighter weight and has revised fin pitch for improved air flow in all riding conditions.
  • Compact, flat radiator fan is lightweight and provides efficient cooling.
  • 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.
  • Durable five-speed transmission with all-new lower ratios designed to match new engine power characteristics.