2-Stroke Tuesday celebrates the enduring legacy of premix-burning machines, both past and present. This week, our focus is on our 2003 Suzuki RM250 project, infused with a touch of Sean Hamblin’s flair, paying homage to his tenure with the factory team.
Reflecting a motocross hall of fame, Suzuki-backed riders of the early 2000s, including Pastrana, Tortelli, Roncada, and Hamblin, amongst others in the 250cc class, vied for the top spot. This rich history inspired our rebuild of the 2003 RM250, igniting our passion for two-stroke engines and the scent of premix and race gas that accompanies them.
Revisiting and reconstructing a 14-year-old motorcycle offers a canvas for the imagination. With this project, we opted for a blend of contemporary and vintage aesthetics.
Beginning such a venture demands patience, as these endeavors are time-intensive and prone to unforeseen challenges. Flexibility is key, as plans often shift, necessitating adaptability. Equipping oneself with a replacement bolt kit from Specbolt or Tusk Racing proves invaluable in navigating unexpected hurdles.
Unlike typical rebuilds, our RM250 remained relatively intact, albeit in semi-functional condition. However, this semblance of coherence belied the challenges ahead.
Upon disassembly, we were confronted with a mishmash of hardware held together by JB Weld and copious amounts of what seemed like super glue. Sending the engine to Matt at L.A. Sleeve revealed a host of surprises.
In essence, both the top and bottom ends of the engine demanded attention. Despite a relatively intact transmission, the clutch bore the brunt of wear and tear. In-house reconstruction of the crank utilized a ProX OEM replacement rod kit.
Addressing the worn cylinder coating, we employed an L.A. Sleeve cylinder rebuild kit. This comprehensive kit included a sleeve, LAPC piston with rings, clips, and wrist pin, along with a new wrist-pin bearing and top-end gasket kit. A ProX basket, inner hub, and clutch-plate kit, inclusive of springs, rejuvenated the clutch assembly.
With major engine work completed at L.A. Sleeve, we integrated aftermarket components from Boyesen. The ignition and clutch cover bestowed a factory aesthetic, while the Supercooler enhanced coolant circulation, complemented by the Rad Valve intake to bolster overall engine performance.
Elevating engine performance, a Bill’s Pipes exhaust system was installed, accentuated by a factory-inspired cone finish on the expansion chamber. Notably, this finish could be applied to any Bill’s Works two-stroke pipes for an additional cost of $125. Rebuilding the Keihin carburetor with an All Balls kit restored settings to OEM specifications.
Turning to the chassis, akin to the engine, extensive refurbishment was essential. Every bearing on the frame, linkage, and swingarm was replaced utilizing the All Balls kit.
Some bearings, corroded beyond salvage, necessitated meticulous removal techniques, including heating and precision use of a Dremel tool. A regimen of maintenance and lubrication could have mitigated these issues.
Suspension emerged as another focal point of the rebuild. Much to our surprise, the state of the suspension surpassed the engine and chassis in terms of deterioration. Salvaging proved futile, prompting the exploration of alternative solutions.
Last year, WP North America introduced the Cone Valve fork and Trax shock kits for contemporary Japanese motorcycles, prompting a decisive shift in our approach. Incorporating newer 450 triple clamps facilitated the installation of an entire front end. The Trax shock underwent modifications to align with the stock 2003 Suzuki RM250 linkage.
With major overhauls completed, attention turned to aesthetics. Drawing inspiration from local talent Sean Hamblin, who earned recognition as a factory Suzuki rider, we amalgamated elements from his 2003 #33 model with the 2004 factory bikes, courtesy of Red Label Graphics.
Remarkably, the hubs remained stock, refurbished by Faster USA, who replaced bearings and fitted Excel gold rims to evoke a factory finish.
This service, offered at approximately half the cost of a new wheelset, exemplifies quality without exorbitance. Departing from the all-black seat of factory bikes, Jeff at SDG injected vibrancy with a custom gripper design in yellow, black, and red hues.
As anticipated, the journey to completion tested our patience. Despite meticulous attention, the tuning process proved arduous, underscoring the idiosyncrasies of older bikes.
However, perseverance prevailed, culminating in a finely-tuned RM250 that captivated onlookers and provided endless enjoyment on the track.
Beyond the mechanical triumph, the camaraderie forged during wrenching sessions underscored the true essence of these endeavors. As one project concludes, the anticipation of future builds beckons, perpetuating the cycle of restoration and exhilaration.
