Cycle News - Archive Issues - 1990's

PROJECT BIKE White Bros. Suzuki DR270 Unfortunately, White is just as - if not more competitive - than myself, and declared that he would do battle at Big Bear aboard the green hot rod. Just as my bubble burst, however, White came up with a solution: a Suzuki DR250 that had undergone the same treatment. Once again, my buddy Tom had come through. DR. JEKYLL AND MR. HYDE By Donn Maeda very October, Cycle News hosts an annual dual sport ride that routes riders through the San Bernardino Mountains below and around Big Bear Lake, California. Among the editorial a!!d advertising sales staff members, the event has become an unofficial "warmup" for our annual Christmas staff race. But wait! A dual sport ride is supposed to be a nice leisurely ride, right? Well, maybe, but anyone who's ever been on a dual sport ride with a /1/otocross racer or two knows how easily these events can turn into one long, extended /1/oto. We confess. Last year, I was talked into participating in what would be my first-ever dual sport E ride and volunteered to ride the Suzuki DR125 that no one else seemed to want. Ignorant of what would unfold on the trail, I figured that the underpowered, undersuspended little machine would be okay for a ho-hum putt down the trail with afew of my cohorts. Little did I know. As soon as 1saw the red glow in my editor's eyes that morning, I knew that I was ill for an adventure. The bar banging started right from the get-go, and I struggled to stay at the head of the pack aboard my miniature mac/line. A flat tire in the first six miles didn't make things any easier, especially since I didn't fix it until the 65-mile //lark. As 1 blew dirt clod after dirt clod from my nose at the end of the day, I vowed to be better prepared for this year's ride... A few months before this year's armual ride, Tom White of White Bros. fame phoned to try and convince me to come out and cover the Four-Stroke World Championship race that they sponsor every year. Sensing my lack of enthusiasm, White sweetened the deal with a White Bros. factory ride aboard their Kawasaki KLX250. Needless to say, the deal was too good to pass up and I agreed. Though the bike started life as a mild-mannered 250, the Kawasaki was punched out to near 300cc and was one of the most fun-toride bikes that I had ever thrown a leg ~ver. It was hard to believe that the bike was street legal, and images of myself winning - oops, I mean riding in the dual sport ride aboard the monster KLX began to flash through my head. This particular bike started out life as an ordinary 1990 Suzuki DR250S, but when the guys at White Bros. were done with it, the docile DR was radically transformed. In stock condition, the DR's weakest link was in the engine department. Though the 249cc, single-overhead-cam motor put out enough power to putt around town on, it left a lot to be desired on the dirt. P\lwer - we wanted more power! "We've tried about every piston, cam and pipe combination on most of the dual sport bikes available," said White. "We try to find the combination that produces the best improvement without sacrificing the reliabillty factor." In the DR's case, a 270cc ki t that consists of an Arias piston and ring kit, a White Bros. All-Around Cam, a Supertrapp E.A.R. muffler and a White Bros. Large Diameter Header was the answer. The high-lift bumpstick opens the valves sooner and quicker, and leaves them open for a longer duration than the stock cam. While the increased overlap yields midrange and top-end gains, most of the motor's bottom-end power is lost. That' where the oversized piston comes in. In addition to adding 21cc, the forged Arias slug bumps up the engine's compression and restores the lost low-end power. The kit still allows room for an additional overbore. In order to get more air into the healthier motor, a White Bros. PowerfjJter was installed and the restrictive stock unit was tossed out the door. TI1e backfire screen was removed from the airbox, and several breather plugs were instalJed into the airbox body. To compensate for the larger engine's greater appetite, the carburetor was jetted richer. Though White Bros. offers larger aftermarket carburetors, we opted to make the most of what we had with the tock Mikuni unit. Spent gasses are expelled through a White Bros. header pipe, which is larger in diameter and is claimed to improve power throughout the entire powerband. A Supertrapp E.A.R. muffler keeps things unrestricted, yet quiet, out back. On the dynamometer, our stock bike pumped out a mere 17 horsepower, but after the White Bros. got to it, the little motor spit out 23. While 23 horsepower may nof sound impressive in comparison to the power output of say, a Honda XR600, consider this - a six horsepower gain for the DR is a 35 percent increase in power. Not too shabby. The second complaint that most offroaders have with the stock DR is that the suspension is too wimpy to handle any aggressive trail riding. Sure, the stock suspender~ are adequate for a 140-pound rider who likes to cruise and take in the scenery, but the stock bike buckles under larger or faster riders. The White Bros. solution? A stiffeT Eibach spring kit. To keep things cost effective, the valving was left alone and stiffer fork and shock springs were relied upon to firm up the ride. Good enough for us. To make the rest of the machine more dirt worthy, a long list of White Bros. accessories were bolted on, most notably

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