Off-road riders who cut their teeth on dirt bikes in the mid-1960s have borne witness to the rise and fall from favor of the two-stroke. From Joel Robert’s first FIM motocross championship in 1964 on a CZ to Suzuki-mounted Ricky Carmichael’s AMA Supercross title in 2005, two-strokes ruled the premium series, earning their dominance the hard way—going head-to-head with the reignin thumpers of the era until they developed enough sophistication to be superior performers.
Helmet: Moose Racing 10X2
Goggles: Scott USA No Sweat IV
Jersey: Moose Racing XCR
Gloves: Moose Racing XCR
Riding Pack: Moose Racing XCR Enduro
Pants: Moose Racing XCR
Boots: Sidi Crossfire SRS. (Click image to enlarge)
The decline of the two-stroke has been as a result of stricter EPA emissions restrictions that favored the cleaner four-stroke motor, which doesn’t spew oil from its combustion chamber into the atmosphere. Additionally, at the racetrack, 450cc four-stroke machines have been allowed to compete against two-strokes with a 250cc limit, giving the valve-and-cam engines the displacement edge they needed to produce competitive horsepower.
The Japanese manufacturers have all but given up on the two-stroke, as they aspire to sell wide-audience four-stroke-powered dirt bikes that meet EPA and state standards for use on public lands, most notably in the large off-road market of California, which requires “Green Sticker” certification for year-around riding. Austrian manufacturer KTM has not surrendered the two-stroke flag yet, continuing to produce a full line with a displacement range from 50cc to 300cc. KTM, of course, also offers modern four-strokes for service ranging from street to supercross. (Click image to enlarge)
In years past, the KTM 300 XC-W (cross-country, wide-ratio gearbox) would have been considered an enduro bike, sporting a head and taillight, which is de rigeur for competition. To avoid EPA oversight, KTM two-strokes are sold without lights, as competition-only closed-course vehicles, leaving it to the buyer to sort out registration (in California, the KTM two-strokes are considered “Red Sticker” machines that can only be ridden in specific areas on restricted dates). Frustratingly, these rules are based on unsound science using flawed data, but the anti-motorized recreation forces were nevertheless able to successfully implement their agenda through brute-force politics.
While two-strokes may have an uncertain future, the latest KTM 300 XC-W shows the technology to be healthier than ever. The kickstarter is the only nod to the past, as the power-valved motor is fed by a 36mm Keihin carb and the plug is sparked by a digital Kokusan ignition. The 293cc engine’s perfectly square bore-to-stroke ratio promises a balanced power delivery, though there is no denying the 300’s abundance of torque that is more than capable of satisfying the demands of the wide-ratio five-speed transmission. (Click image to enlarge)
The chassis is equal to the motor. The main frame is chromoly steel and the subframe aluminum, affording the XC-W a wet, unfueled weight of 225 pounds, less than the Honda CRF250X or Yamaha WR250F thumpers. Foot-long travel WP suspension features a full range of damping and spring adjustment. In the rear, the WP shock is bolted directly to a linkage-free aluminum swingarm, for reduced weight, reliability and ease of maintenance.
Quality bits are abundant on the XC-W: wide chromoly footpegs, Brembo hydraulics, bulged Magura X-line aluminum bars with dual-compound Renthal grips, lightweight magnesium covers for the ignition and clutch. An FMF Turbine Core 2 spark arrester was installed to establish legality in the National Forests without power reduction.
The 300 XC-W serves two purposes: it is a competitive race machine and an amenable trail bike. Although we didn’t race the 300, it wasn’t reluctant to verify its mettle when pushed to fighting speeds. The motor, though of open-class displacement, tenders much of the instant throttle response you’d expect from a 250. This allows a rider to quickly power his way out of trouble, yet the abundant torque allows short shifting the 300 if desired. More than up to the challenge presented by the plentiful power, the WP suspension is taut, yet never harsh. Wallowing is banished, as the versatile intermediate terrain Bridgestone tires assist in the KTM’s delivery of instinctive handling. In a straight line, the 300 is planted and secure, though the addition of an adjustable steering damper would not draw a complaint. Flawless ergonomics add the finishing touch to an outstanding handling package.
Race bikes often do not function well for more temperate riding, but the 300 XC-W is an exception. Most trail riders enticed by the KTM will push it hard enough to appreciate the superbly damped, sprung and balanced suspension. Lacking any handling or suspension gremlins, the rider can concentrate on the spectacular motor to take him anywhere he chooses to ride. Hillclimbs that recall the Matterhorn (both in the Alps and at the late Saddleback Park) may intimidate the rider, but not the unflappable XC-W. At the other end of the scale, picking through rocky streambeds and winding gulleys is nearly effortless, as the KTM is willing to traverse extreme terrain at low speed without complaint and with propitious accuracy. Spot-on carburetion, a healthy spark, an efficient lever and VP Racing Motorsport 103 fuel (mixed with Motul 800 two-stroke oil) alleviate the chore of kickstarting the 300. (Click image to enlarge)
As impressive as the newest generation of four-stroke dirt machinery is, it’s disappointing to watch the extinction of the two-stroke off-road machine, and such outstanding machines as the KTM 300 XC-W makes that process just that much more painful.