2003: WR450F
Major changes
Engine
• All-new lightweight 450cc DOHC liquid-cooled 4-stroke engine
• Compact and lightweight electric starter with kickstarter
• New camshaft with compact automatic decompressor
• Convenient handlebar mounted hot start lever
• Wide ratio 5-speed transmission
• Larger-capacity radiators
• Quick-release airbox with left side cover opening
• 95 x 63.4mm bore & stroke
• New ultra-compact 5-valve cylinder head
• Shorter titanium valves and more compact valve springs
• New design compact cam chain tensioner
• New design lightweight forged piston
• Modified primary driven gear with rubber dampers
• Redesigned crankshaft assembly
• Modified carburettor with optimised settings
• Improved airbox joint design
• Spark plug cap integrated ignition
• New design CDI unit
• Smaller oil pump
• New type oil filter
• New aluminium oil hoses
Chassis
• New design mass-centralising 10-litre fuel tank
• Fully equipped with front and rear lights
• 18 inch rear wheel
• Steel rear sprocket
• Sidestand
• All-new semi-double cradle frame with improved balance and rigidity
• New lightweight square section aluminium subframe
• Radical new ‘wedge’ style tank/seat/radiator air scoops
• 5mm shorter wheelbase
• Flatter seat with special 3-layer polyurethane material
• New-shape rear fender, radiator scoops and sidepanels
• New shape integral oil tank with relocated filler cap
• Lightweight rear upper engine mounting bracket
• New two-piece resin/aluminium engine protectors
• Lighter engine sidecase guards
• New design lightweight anodised swingarm
• Lighter front caliper with aluminium pistons
• Modified front brake master cylinder
• Lighter rear caliper, caliper bracket, pads and caliper protector
• Integrated rear brake master cylinder and reservoir
• Modified swingarm seal guard
• New design chain support
• New style fuel tank cap
• New lightweight throttle and clutch cables
