Having spent considerable time this past season aboard a 260 two-stroke (which we literally boxed up for shipment the day before our departure to Utah), we were well primed to see where the company was headed. You'll recall that last year, after ample fiddling, we found the 260 LQ to be a pleasant trail bike and competitive racer, but not without warts. Many of those issues identified here in Trail Rider have been smoothed out (perhaps surprisingly so) in the '97 model line. Additionally, we got some fresh first hand experience aboard the trick ATK four-strokes, 350 and 605 cross country (off-road) and dual sport models and finally, a peek into what lies just around the corner for the USA's only dirt bike manufacturer. Here's what to look for from ATK in 1997.
Both the 250 and 260 LQ models are back for '97, graced with some refinements. For the record, the 250 LQ is a true 250cc motor, while the 260 is actually a 251cc hybrid, its bore "hogged out" a mere 0.15mm. Both bikes are still feather weights in enduro trim, with a claimed (and pretty darn close to what we measured last year) 235 pounds dry. The enduro kit (skid plate, spark arrestor, lighting kit) are options on the 250 while standard on the 260 model. Using the laudable "if it ain't broke, don't fix it" mentality, the '97 two strokes return with plenty of the same world class hardware we've come to expect from ATK. This includes stout Pro-Taper handlebars, trick-looking gold anodized Talon hubs, and self-cleaning Answer Radialite rear and front steel sprockets, driven by a DID O-ring chain. Proven Dunlop intermediate terrain knobbies, a D737 rear and K490 front, compliment White Power suspension components and keep things in good contact with whatever ground'is being traversed. The same Rotax liquid cooled motors with 6 speed, wide ratio transmissions develop obligatory motive power and exhaust through a nickel plated pipe and aluminum silencer or silencer/spark arrestor combo unit. An SEM ignition gets things spinning and is replete with a 160 watt lighting coil.
Finally, a 3.1 gallon fuel cell with integral bullet-proof radiator shrouds ensures you'll never worry about brush tearing off radiator plastic, or fuel problems completing those 50 mile enduro loops. In the new and improved category, '97 ATKs come with a beefy new chain guide that'll surely stand up to the worst use and considerable abuse. A new subframe bracing scheme better supports the enduro fender, tail light and license plate mounting assembly, keeping that hungry rear knobby from chewing up plastic.
Last year's problems with the rear brake master cylinder support bracket have been fixed, this year made from stouter chrome moly steel. It turns out, last year's frame weldment was mistakenly made with a mild steel mounting bracket, hence the bending problems previously noted. The '97 LQs have a slightly taller saddle made from denser foam that retains a good shape and feel for maintaining proper body position. A smaller Mikuni TMX carburetor (35mm vice 37mm) was an attempt to get some more bottom end power while smoothing out the high end hit of the Rotax power plant. While we welcome any gains in this area, the Rotax power plant still has room for improvement. The Rotax two-stroke is still a very mild motor. Finally, the '97, two and four stroke models come with a new White Power fork that eliminates the rebound and two-stage compression damping adjustments (read: a single compression damping adjustment only). We liked last years fork, being the fiddlers that we are, however some tuners will claim that all those extra adjustments are an overkill. Rest assured, we'll prove this to ourselves, one way or another, once our '97 test bike arrives.
The ATK four strokes have the undisputed, trickest frame in the business. Introduced in '96 and back for '97, this cool asymmetric flying "V" chrome moly backbone is a feather weight that makes the engine a stressed member. When ATK builds these models, the frame is bolted onto the motor, rather than the motor being bolted into the frame. It's awesome. Oil from the dry sump Rotax power plant is carried in the frame back bone to the tune of three quarts, which further aids engine cooling. Four stroke 350 and 605 models can be had in cross-country and dual sport trim, with primary kick or electric starting. Dual sport models are 100% identical to their cross-country brethren, save the additional street hardware like signals, horn, mirrors, battery and substantial wiring harness. All the important stuff, i.e., suspension, motor and carburetion, are shared. Regarding the electric start option, it adds 12 pounds, and in our opinion is a small price to pay to avoid kick starting these beasts. Also noteworthy, there is only a two pound difference between the 350 and 605 models.
The venerable Rotax counter-balanced, belt driven, single overhead cam four-stroke motors are solid, if not somewhat dated power plants. The 350 and 605 engines weigh in at 348cc and 598cc, respectively. In the stock state of tune they provide long life and good linear power. For racers and/or other horsepower hounds, there are plenty of aftermarket tuners out there that can turn these dependable prime movers into real fire breathers. However, beware of increased difficulties in kick starting high compression motors. A Nippondenso electronic ignition includes a 190 watt lighting coil that is standard on the dual sports and optional on cross country models. Carburetion is via 34mm and 40mm Dell'Ortos, for the 350 and 605, respectively, while all models exhaust through a stainless steel header pipe and tunable, lightweight SuperTrapp muffler system.
Regarding power output, our seat-of-the pants impression puts the 350 somewhere in the middle of the midsize thumper class. Not the same raw, revving, explosive power of the Husaberg 400, however, easily stronger than current stock KLX300, XT350 and DR350 motors. The 605 is a bit tougher to place. The counter-balanced motor is easily smoother than the output of, say, the Honda XR650L, but it's otherwise hard to distinguish it from other open class thumpers, like the XR600, KTM 620 or Husky 610, without a side by side comparison. This is probably good, as each of those other bikes have distinguished themselves on many occasions as proven trail bikes and racers.
The '97 ATK four strokes get the same, albeit differently sprung and valved, new White Power fork as the '97 two stroke models. Same goes for saddle upgrades (denser foam and slightly taller), drive train (Answer Radialite rear sprocket, DID O-ring chain) and tires on the cross-country model. Dual sports come shod with DOT approved Dunlop knobbies, a D905 front and D903 rear. Rounding out the package, a trick aluminum air box is an integral part of the subframe while a voluminous 3.6 gallon fuel cell remains plenty skinny as a result of the economies of the flying "V" frame. So, what's the verdict? ATK thumpers are a force to be reckoned with in desert racing out west, and can be a capable dual sport mount anywhere. The third production year of the liquid cooled two stroke models finds further refinements, contributing to a niche-oriented package for riders who don't want to ride a CR250 in the woods. Quite frankly, ATK continues to amaze us with a world class product built here in the USA by a small cadre of dedicated motorcycle enthusiasts. Look to Trail Rider for some future in-depth testing of the '97 ATKs!