Most people think that you need an old-school motorcycle to handle old-school desert races—big, fast and heavy. That’s the way Jack Johnson and Walt Axthelm did it, by George, so that’s the way it should be done, right? Maybe not. This bike was built especially for the Best in the Desert series and it was based on a bike historically relegated to campgrounds and picnic areas. The Yamaha WR250F has a very unadorned racing history, but we decided that should change. Last year the WR was completely redesigned with more YZ-think than ever before. It’s time it earned a racing pedigree.

We admit that a 250cc four-stroke isn’t the right bike if you’re aiming for the overall win. We weren’t thinking in those terms. A top five and perhaps a class win, however, are perfectly within reach for a small-bore four-stroke. The WR can do that and beat its share of larger-displacement bikes along the way, because it can easily be made to produce as much power as the YZ version, and it has a wide-ratio gearbox for those long stretches of open Nevada desert. Also, the mass starts that favored big bikes are long gone. Most long-distance races are timed nowadays.
The first part of the WR’s conversion is easy. Yamaha’s accessory division sells a power-up kit that has a different CPU for the ignition and a new throttle stop. Remember, the WR250F is sold as an off-road model that meets EPA and CARB emission requirements. In stock form, the throttle doesn’t open all the way. To finish the competition conversion, you need an exhaust like the FMF F4.1 Ti system. Even with the accessory black box the WR still doesn’t quite run like a YZ, unless you do a little remapping using the Yamaha Power Tuner. If you have time to do your own testing, it’s not a difficult process; you can simply add fuel and advance the spark until it feels faster. In this case, we used a more efficient method. We installed a Dynojet Power Commander with settings worked out by Jett Tuning. The motor was geared up slightly with a 14/48 sprocket combination. The WR still has a decently low first gear, but Vegas to Reno also has its share of technical sections, so we installed a Rekluse Core EXP 3.0 automatic clutch just to help eliminate the possibility of stalling. We still had the WR’s electric starter; we don’t understand why anyone would disable that for the scant weight savings. In fact, you need a battery and a headlight for some races–Baja and Vegas to Reno, anyway. The stock headlight isn’t worth much, but the Baja Designs Squadron Pro is a compact headlight that doesn’t require any more space than the stocker and produces about 10 times the light using four small LED lamps in a Polysport plastic frame. It costs about $250 but bolts on to the WR without any stator work or anything. We used an EarthX lithium-ion battery to power the light, the starter and everything else, because it weighs 2 pounds less than stock and has greater capacity.

Troy Vanscourt explores some southwestern terrain on the converted WR250F.

You have to increase the range of the WR just a bit. The fuel stops are typically around 30 miles apart, which is well within the bike’s stock range. But, some go beyond 50 miles and require increased fuel capacity. IMS sells a wing tank that holds 3.2 gallons, meaning it eliminates the radiator shrouds and carries some fuel outboard of the radiators. Switching tanks is also a good idea because you can use an IMS dry-break quick-fill system.
Beyond fuel range there’s human range. Just because a motorcycle can go 70 miles on a tank of gas doesn’t mean the rider can. Seat Concepts specializes in making seats that are good for hours and hours. In this race that’s particularly important. There are rough parts, silty parts and technical parts, but there are also sit-still-and-pin-it parts. Along the same lines, suspension work and a steering stabilizer make the trip less grueling. The WR’s stock suspension is outrageously good for trail riding but not for crossing states at race speed. TBT Racing did the suspension work for about half what other companies charge—and did a good job. Then, a GPR Version 4 stabilizer went on with a billet top clamp.
Survival parts that were left: a Boyesen Supercooler, Pro Taper Fuzion bars and levers, MSR radiator braces, UFO plastics and chainguide, and a PC3 carbon skid plate made the bike just a little tougher.

What started off as a fluffy trail bike is now a fluffy race bike.

We’ve had the bike up to 94 mph. It takes a little more room to get up there than a big bike, but we’re quite sure we don’t want to go any faster. The result that we’re most pleased with so far is the fun factor. Riding the WR is an absolute blast. When you get it up to nearly 100 mph it’s not scary at all. You feel like you can stop quickly and dodge any rampaging Nevada burros that wander onto the course. With enough time in top gear, slowing down to 50 mph feels like walking speed.
High-speed cross-country racing is downsizing almost everywhere in the world. We’ve seen the winners in the Baja 1000 shift from 650s to 450s in the last 10 years. In Dakar the bikes were 1000cc, then 650cc and now 450cc. We admit, we’re a little ahead of the trend, using a 250 but trust us; it’s the way of the future, and we like it.


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