Yamaha Wr250f
Yamaha WR250F
CYCLE WORLD TEST
Thump-thing for the woods
BRIAN CATTERSON
IF A DIRTIBIKE FALLS IN THE FOREST AND NOBODY else hears it, did it fall at all? I ask this because I'm deep in the woods of South Carolina, deeply embarrassed that the other guys are having to wait for me, I'm sweating bullets, my goggles are completely
fogged over and if I have to kickstart this friggin' diesel one more time, I'm gonna kill someone! Which, considering that I'm the only one around at the moment, is probably a bad thing...
I’m here with select members of America’s motorcycling press as guests of Yamaha and Randy Hawkins, umpteen-time national enduro champion and the lead rider for the East Coast arm of Yamaha’s off-road racing effort. The puipose of our visit is to test ride the new WR250F enduro bike in its native habitat, the woods.
Wait a second, did I say WR250? Wouldn’t that make it, like, a quarter-liter off-road four-stroke? That’s traditionally been the domain of half-hearted trail wheezers like Honda’s XR250-playbikes better suited for kids and wives than serious off-roaders. Hasn’t it?
Well, that was then and this is now, and ever since Yamaha re-wrote the rules on what we can expect from a four-stroke, it’s been a non-stop learning experience. Latest lesson is in the West Coast 125cc Supercross series, where fourstrokes-previously considered un-raceable-are allowed twice the displacement. Ernesto Fonseca has turned the class upside-down, taking his new YZ250F Thumper to the top of the box in four of the five races to date.
And now comes the YZ-F’s off-road-oriented sibling, the WR250F. Based on the YZ, the WR follows the format of its larger 400 and 426cc siblings in that it is a re-tuned version of the motocrosser aimed at enduro and cross-country racing.
It’s powered by the same basic engine as the YZ-a liquidcooled, counterbalanced, gear-driven dohc Single with direct, shim-under-bucket actuation of its five (count ’em) titanium valves. Four-stroke engines traditionally employ larger-diameter intake than exhaust valves because the incoming fuel/air mixture is larger in volume than the outgoing exhaust gases. But Yamaha’s five-valve engines take a different route; they utilize three smaller (23mm in the WR’s case) intake and two larger (24.5mm) exhaust valves to achieve the same effect.
Changes from the YZ to the WR engine are surprisingly few. As on the larger WRs, the exhaust cam was rotated one tooth, changing exhaust cam timing from 105 to 127.5 degrees, and a larger-diameter (though only slightly heavier) flywheel makes for higher inertia, both in the interest of smoothing power delivery. Carburetion is via the same throttle-position-sensor-equipped 37mm Keihin as on the YZ, except that the WR’s has an anti-backfire valve to prevent the air filter from catching fire while you’re coasting downhill. A higher-output CDI unit works in conjunction with a voltage regulator to power the 60-watt halogen headlamp and taillight, while a larger radiator with one additional tube provides extra cooling for slow going.
Speaking of slow going, as its name implies, the WR is equipped with a wide-ratio transmission. Compared to the YZ, the WR has a lower first gear, the same second, a taller third, a fourth identical to the YZ’s fifth, and an overdrive fifth. In spite of shorter final gearing (13/52, compared to the YZ’s 13/48), the WR is said to be good for a higher top speed, in the vicinity of 80 mph.
Chassis-wise, the WR is identical to the YZ save for its WR426-derived steel (rather than aluminum) subframe and 18-inch (as opposed to 19-inch) rear wheel. Lastly, the WR benefits from enduro amenities such as an odometer, spark arrestor, larger fuel tank with Reserve petcock, sidestand, left-side engine guard (the YZ only has one covering the water pump on the right), longer-lasting O-ring chain and steel rear sprocket.
To introduce the WR250F to the press, Yamaha flew us to Travelers Rest, South Carolina, a town that earned its name as a popular stopover point for horse-drawn wagons. These days, it’s better known as the home of Randy Hawkins. It still lives up to its name, though, because after two days of riding in Randy’s backyard-literally-even we mechanized travelers were in dire need of rest.
“We’ll take you through trails most could not walk,” exclaimed Yamaha PR guy Terry Beal’s invitation. And he was right, except that I never actually saw any trails. All I saw were trees-lots and lots of trees, every 4378th one tied with day-glow orange ribbon. If you got separated from the group for just a few moments, it was a chrome-plat ed bitch figuring out which way they went. I felt like a paleontologist searching for signs of past civiliza tion-fossilized tire tracks in the mud, leaves swirling in a vortex or blue-plastic rubs on tree trunks. Someone said to follow the arrows, but I never even saw the Indians!
We spent the first day familiarizing ourselves with the WRs on Randy's backyard motocross track and an ISDE-style grass track set up in a farm field across the street. There, watched by grazing buffaloes and llamas (no, I'm not making this up), we quickly came to appreciate the WR's light weight and user-friendly nature as we slalomed through trees so tightly spaced, we had to wag one bar end through at a time. Yamaha had thoughtfully equipped each testbike with a pair of accessory handguards, and these soon bore the marks of close encounters of the barked kind.
You might expect a 250cc four-stroke to be slow, but that was the last thing on my mind as I held the throttle wide-open and banged upshifts on the short straightaways connecting clumps of trees. Compared to the YZ25OF, the WR makes its peak power soon er, but thanks to its larger flywheel that delivery is slowed down a tad, and is thus smoother and more tractable-helpful when you're trying to claw your way out of a rutted, root-covered, off-camber corner. Yet the engine still revs quickly, and still zings to its 13,500-rpm redline, giving you loads of overrev for those straightaways that don't quite warrant another upshift/downshift.
Day two saw the aforementioned trail ride/death march, wherein we spent nearly three hours in the woods and went just 16.4 miles! I think they made bet ter progress in the Blair Witch Project. Yet throughout all the tough slogging, the WR was a willing compan ion, always hooking up instead of spinning, climbing stupid-steep hills with relative ease, seemingly bending around trees and never once threatening to throw me down. To the contrary, I once threw it down-or more accurately up-hucking it over a sheer rock face when the trail took a sud den, surprising turn toward the vertical. Maybe the other guys were just patronizing me, but no one said anything derogatory as they scrambled to stop my bike from tumbling back down the cliff~ one even went so far as to shout, "Hey, nice Gilles Lalay move!" (Note to the uninformed: The Gilles Lalay Classic is a masochistic off-road event wherein competitors routinely per form just such histrionics. Apparently, few finish.)
Prior to our trail ride, a couple of testers voiced concerns that the WR's suspension might feel harsh in the woods, because the only changes from YZ-spec are lighter mid speed damping. And maybe it would be for lighter riders, or those accustomed to running over logs buried under a foot of leaves. But it felt fine to me, and I didn't hear anyone else complaining after the ride.
In fact, the only real negative comments regarded the eardrum unfriendliness of the de-bunged muffler and the motor's tenden cy to stall if you lugged it down too low in second gear instead of downshifting to first. Then there was the subsequent difficul ty restarting it: Apparently, you need to exercise a bit more fmesse when squeaking it past TDC with the compressionrelease than you do with a 400 or 426. Unfortunately, I didn't learn this until late on the second day, by which point I'd devel oped a charlie horse. Other than that, though, it was all smiles. And consider this: Riding a YZ25OF against a full field of two-strokes and 400cc-plus four-strokes, Ty Davis stormed to fourth place overall in the inaugural World Off-Road Championship Series race at Glen Helen in California. And Randy Hawkins says that once the National Enduro Series gets past the initial fast West Coast races, he's going to trade in his WR426F for a WR25OF, because he can go faster on it in the woods.
Funny, I don't hear anyone laughing.
YAMAHA WR250F
$5699
