2003 Yamaha YZ450F

Four-Stroke Competition Bike for the Masses

Lake Whitney, Texas, August 30, 2002 -- The Fed-Ex man arrived at Hatch Studios with plane tickets and a packed itinerary straight from Yamaha -- my new MO mission was going to Lake Whitney, Texas for a chance to ride the all-new 2003 YZ450F. I was apprehensive at first -- I'm a reborn dirt rider on my WR 400 with very little MX track time. But, I figured a chance like this might only come around once, so I would give it my best shot and apologize later. The tone of this first-class affair was set early in Texas when I was greeted by a Cadillac Escalade stretch limo. After picking up the wild boys from "Motoworld" we were on our way to the luxurious WB Ranch.

Morning broke with an informative presentation covering some of the 180 changes made to the big YZ; this was not a massaged 426 but a whole new animal. I looked forward to mounting the 13.5-pound lighter machine and putting the staff catch phrase of "flickable" to the test. Nothing about me or my riding style has ever had the term 'flick' associated with it, but that's not the bike's fault. The slick graphics pointed out the average age of the new YZ buyer -- about 33 years old -- and many of the bikes would never see competition on a track. That was me, I had my own piece of the pie chart: I grew up in that odd category of kid who used a motocross bike for anything and everything but motocross, like mowing through the woods or tearing up the local sandpit. Maybe you know the type or were one yourself.

Tiny new hot start lever.
  We loaded up and headed down the road past the exotic game roaming the ranch to the beautifully maintained Lake Whitney MX track with a row of new 450s and support staff waiting for us. Before I headed out I was told to just learn the track first before I got on it. No worries there, I was cautious to say the least as Burns stressed that my prime objective was to return uninjured, but I sort of had this in mind before his orders came down the line. Visually the new bike has a compact and aggressive stance compared to the last generation.

Once in the saddle the work area was impressive with a new flatter tank and seat junction and aggressive riding position. I would have to learn to sit forward now that I could, compared to my big old WR tank. Ergos were quite roomy for my large stature and after a rear brake adjustment things were good to go. I headed out on my reconnaissance lap gently wicking up the pace with each turn. The 450 felt very forgiving in any circumstance and gave me the utmost confidence tackling any obstacle I encountered while lapping the loamy track. I found the power from the extra 23ccs added this year to be very linear with more than enough on tap anywhere in the rev range to blast me over a set of woops or straight up the face of a jump with little effort. The trans is now a four speed down from five and made perfect sense since I would only climb as high as 3rd during my time at the track.

Trying to get off the ground for Frank's camera.
Don Dudek offers some advice to the exhausted Hatch.
This is the time when those stiffer springs would come in handy.
One of the most revolutionary changes has to be the automatic decompression system which means you just kick it and if things are hot simply pull the handlebar mounted hot start lever and that is it. For those of you familiar with the old drill of the compression release lever, finding top dead center often in hot or awkward situations on the trail or track, you can appreciate the magnitude of this change. Minimal effort is now required to get things lit.

As I got more comfortable with the track and bike I could get a feel for the suspension, the bike felt very neutral over the rough stuff and even during the minimal air I could muster. I probably could use a stiffer set of springs front and rear to go beyond a playful pace but I am sure my personal dimensions are outside the parameters the Yamaha staff worked toward.

The Yamaha staff was great acting in a very accommodating and understanding manner. I had a chance to work with photographer Frank Hoppen who has to be the hardest working man in show business. He did his best to capture me digitally not looking too out of my element. While taking a break from the oppressive Texas heat I climbed to the top of a tower to watch Doug Dubach hammer around the track showing the true capabilities of this bike. The thundering exhaust note made it clear Doug rarely gets off the pipe while ripping his way around the track; it was an impressive sight to behold to say the least. In the right hands this bike is capable of amazing things.

  I feel the YZ 450 has finally reached maturity with the 2003 model and Yamaha has created a confidence-inspiring bike that enables the rider to reach the limits of their ability without any drama or stress. There are no longer any compromises when going with a four-stroke. This is the 450 MX bike for 2003 but I may need to mount the rival Honda to confirm my opinion.   

2003 Yamaha YZ450F Specs               
Type: 449cc, DOHC, 5-valve, liquid-cooled
       four-stroke w/ titanium valves
Bore x stroke: 95x63.4mm/3.74x2.5in
Compression ratio: 12.5:1
Carburetion: 39mm Keihin FCR Flat-side w/TPS
Transmission: Constant mesh 4-speed,
              multi-disc wet clutch
Starting: Kick
Frame: Semi double cradle
Front suspension: Telescopic fork, 11.81"/300mm travel;
                  coil spring/oil damper
Rear suspension: Swingarm link suspension, 12.4" travel;
                coil spring/gas-oil damper;
                separate hi/lo-spd compression adjustment
Rake: 27.2°
Trail: 4.65in/118mm
Front brake: 250mm floating disc
Rear brake: 245mm single disc
Front tire: 80/100-21 Dunlop 739
Rear tire: 110/90-19 Dunlop 739
Overall dimensions (LxWxH)- 85.5x32.6x51.3"/2172x828x1303mm
Seat height: 39.2"/996mm
Wheelbase: 58.5"/1486mm
Ground clearance: 14.6"/371mm
Fuel capacity: 1.8gallons/8.2L
Dry weight: 222lbs/101kg
Colors: Team Yamaha Blue/White

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