Project 2003 Yamaha WR450F - OLD - - Dirtbike at Off-Road.com

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Project 2003 Yamaha WR450F - OLD

Publish date: Nov 1, 2005
Source: Dirtbike at Off-Road.com

Blue Bikes That Made Everyone Play Catch Up

We’ve made our decision that the new ORC/MxOffroad.com project bike will be the 2003 Yamaha WR450F. If you manufacture aftermarket parts and would like to be involved, shoot me an email at: mhobbs@off-road.com with "WR450F Project" in the subject line of the email.

Yamaha revolutionized the 4-stroke off-road motorcycle world in 1998 with the release of the YZ/WR 400. Previous 4-strokes paled in comparison to Yamaha’s new high performance liquid cooled thumper. We bought, abused and tested the 1999 WR400 and it hung tough throughout everything we could throw at it. This is a major reason we decided to long-term test the 2003 WR450F. Only time will tell if the new hybrid lives up to its predecessor’s standards. Without any real competition from the Red, Yellow and Green teams Yamaha upped the displacement of the hugely popular YZ400 in 2000 to 426cc’s and left the WR at 400cc’s. KTM offered up their race monster 4-strokes in 2000 as well, putting a dent in Yamaha ownership. KTM’s are quality bikes and you pay for that quality with $1,000 added to the price tag compared to the Japanese manufactures. Although KTM ownership is on the rise they still don’t sell as many bikes as Yamaha. In 2001 the WR got the 426cc motor, then rumors late in 2001 had folks chopping at the bit that Yamaha had a 450 in the works with a 2002 release date. This turned out to be just a rumor that must of had some kind of basis in reality, because in 2003 the YZ/WR450F’s are due to hit showroom floors by December. Honda’s 2002 release of the CRF450 4-stroke had folks riding red in mass quantities once again. This may have kept Yamaha honest but off road riders were disappointed in the race-bred Honda for off road use.

"If you want to ride MX, buy a bike that’s made for that purpose and don’t try and turn a MX bike into an off road bike". Rick "Super Hunky" Sieman enlightened me with these words many years ago when I showed up at his casa in Baja on a two-stroke MX bike converted for off road use. At the time, I thought, what does this old turd know? Then one day I realized the old fart knew what he was talking about as I ran out of two-stroke oil in the middle of the Mexican desert. Another old time super rider Bill Salzman gave me a tip that to this day still rings true. If you want a dual sport bike, buy two bikes, one for street use and the other for dirt use. These old timers would still whip most riders if given the chance but their knowledge is well beyond their decades of experience. The new Yamaha YZ450F is an MX only machine! Reports are that it only has 4 gears and its job in life is to win races on a MX track. While some folks might convert it for off road use, the gods of the past know best, why not get the correct weapon for the job? So, when I see you knuckleheads on the trail stalled out because you didn’t heed the warning, you’ll know I have a smirk on my face. Pre release specs on the 2003 WR450F seem to indicate this new machine might throw the standards of the past out the window. Could this finally be the bike that breaks down the walls and does it all? No one is saying what it will weigh but if it’s the same 255 pounds (dry) as the 2002 WR426 with the addition of an electric start it just might be the Dual sport ready machine that the on/off road crowd has been begging for. As you can tell, we have a lot of questions and not many answers at this point but that should change sometime in November. Until we get our hands on this baby, let’s take a side-by-side look at the 2002 WR426F and the 2003 WR450F, shall we?

Model	2002 Yamaha WR 426 F	2003 Yamaha WR 450 F
MSRP	$6,199	$6,399
Engine	426cc liquid cooled, 5-valve DOHC, four stroke, titanium valves	449cc liquid cooled, 5-valve DOHC, four stroke, titanium valves
Bore/Stroke	95 x 60.1mm	95 x 63.4 mm
Final Drive	#520 O-ring chain	520 chain
Compression Ratio	12.5:1	12.5:1
Carburetion	39mm Keihin FCR flat-slide w/throttle position sensor	39mm Keihin FCR flat-slide w/throttle position sensor
Ignition	Digital CDI	Digital CDI
Transmission	Wide-ratio, 5-speed w/multi-plate wet clutch	Wide-ratio, 5-speed w/multi-plate wet clutch
Front Suspension	46mm Kayaba inverted telescopic fork w/adjustable compression and rebound damping	46mm Kayaba inverted telescopic fork w/adjustable compression and rebound damping
Travel	11.8	11.8
Rear Suspension	Kayaba single shock w/adjustable preload, compression and rebound damping & separate hi/b-speed compression adjuster	Kayaba single shock w/adjustable preload, compression and rebound damping & separate hi/b-speed compression adjuster
Travel	12.4	12.4
Tire - Front	80/100 21 Dunlop	80/100 21 Dunlop
Tire - Rear	110/100 18 Dunlop	110/100 18 Dunlop
Length	85.5"	85.4"
Width	32.6"	32.5"
Height	51.3"	51.2"
Seat Height	39.3"	39.2"
Wheelbase	58.7"	58.4"
Ground Clearance	14.7"	14.6"
Dry Weight	240 lbs.	TBA
Fuel Capacity	3.17 gallons	2.6 gallons
Color	Team Yamaha Blue/White	Team Yamaha Blue/White

Here are the claims that Yamaha has made letting us know that we really need this motorcycle! ALL-NEW FOR 2003:

The industry's most powerful and most advanced 4-stroke Enduro machine returns stronger, lighter and better-handling than ever - and featuring all-new, super-easy electric starting!
All-new, liquid-cooled, 449cc, 5-valve, DOHC, 4-stroke with titanium valves features longer 63.4mm stroke (up from 60.1mm) and completely new-design cylinder head, piston and crankshaft, delivering flatter, broader torque (for instant hook-up) with higher over-rev capacity and crisper, more linear throttle response.
Cylinder head is smaller in design for reduced weight.
All-new, lighter-weight crankshaft helps decrease inertial mass by 20%, reducing friction for faster-revving low-rpm response.
New-design piston features shorter skirt and smaller pin boss diameter to help reduce weight.
Shorter, lighter-weight titanium valves and load-reduced springs are nearly 20% lighter, further reducing reciprocating mass for faster-revving, harder-hitting power delivery across the rev range.
Additional weight-reducing engine upgrades include: smaller-design cam chain tensioner and oil pump; aluminum oil hose (was steel); all-titanium exhaust header, flange, bracket and heat shield; and lighter CDI ignition unit, coil ad magnet rotor.
Retooled carburetor features throttle cover with improved sealing and all-new hot start system with convenient, handlebar-mounted lever.
Larger-capacity radiator and louvers ensures maximum cooling efficiency.
Redesigned airbox features all-new retaining bracket for improved sealing.
Super-strong twin-spar frame redesigned with reduced weight and greater lateral rigidity for minimal flex and razor-sharp handling.
All-new tapered swingarm features less weight and greater rigidity for more compliant rear suspension action.
Recalibrated front fork settings deliver improved damping force with less bottoming for a smoother, more compliant overall stroke.
Rear shock refinements include improved actuation, a new linking ratio and enhanced damping force.
New-design removable aluminum rear subframe reduces weight and allows easy maintenance.
All-new, lighter-weight front and rear master cylinders and calipers, combined with 250mm fully floating front and 245mm rear disc, delivers stronger stopping power with greater, more progressive control and feel.
Retooled steering crown combines with all-new bodywork - flatter seat, fuel tank and radiator shrouds - creates a more aggressive riding position while allowing optimal rider movement.
More weight savings come via all-new, two-piece (part
aluminum, part plastic) engine protector plates and thinner-walled engine guard construction.

Engine:

All-new automatic decompression system eliminates manual lever, ensuring easy restarts in any gear.
Liquid-cooled, 449cc, 5-valve, DOHC, 4-stroke produces tremendous, hard-hitting low- and mid-range torque and a broader powerband tuned specially for enduro/off-road
performance needs.
39mm Keihin FCR flat-slide carburetor with throttle position sensor (TPS) ensures ultra-precise fuel/air mixing and lightning-quick throttle response.
Digital CD ignition system delivers more precise spark and monitors engine speed to ensure optimal timing for faster, stronger response during hard acceleration.
Slick-shifting, wide-ratio, 5-speed transmission with YZ450F-spec, multi-plate clutch geared specially for quick-hitting power in woods and hard-pulling top-end on wide-open trails.
Lightweight exhaust system maximizes engine power and allows hassle-free replacement of oil filter.
Stainless steel muffler with USFS-approved spark arrestor looks trick and resists corrosion.
Electric starting and kick starting (with all-new automatic decompression and hot start lever) ensures easy restarts.
Trick, works-style clutch lever features oversize barrel adjuster for easy, on-the-fly adjustability of lever/cable play.

Chassis/Suspension:

Removable aluminum rear subframe constructed of square-section pipe for reduced weight.
Lightweight 46mm inverted Kayaba cartridge fork features 11.8" of travel with compression and rebound damping adjustability.
Low-friction outer tubes and aluminum piston rods ensure smooth, compliant fork stroke for superior handling and light steering.
Rear suspension system features fully adjustable Kayaba shock with 12.4" of travel and separate adjusters for high- and low-speed compression damping.
Lightweight 21" front and 18" rear Excel rims provide exceptional durability and help reduce unsprung weight for optimal suspension performance.
Premium Dunlop 739 knobbies offer unbeatable, competition-spec traction and excellent wear.

Additional Features:

Enduro-legal lighting front and rear increase versatility by maximizing nighttime and low-light visibility.
Large, 2.6-gallon fuel tank ensures excellent range.
Resettable tripmeter allows rider to keep track of both mileage and fuel reserves.
Wide, cleated, folding cast alloy footpegs provide excellent comfort, grip and ground clearance.
Adjustable front brake lever.
Cleated rear brake lever and folding shift lever tip offer superb grip and excellent durability.
Lightweight aluminum kickstand adds convenience and tucks up high when not in use.
Stylish Team Yamaha-inspired two-tone (black/blue) seat.
Repackable exhaust silencer.
Durable, comfortable handlebar grips.
Stainless steel clutch cable for longer life.