Two-Stroke Tuesday | The SML Red Bull Straight Rhythm Suzuki RM250

Last May, our buddy Alex Ray was perusing the Facebook Marketplace and came across a 2003 Suzuki RM250 two-stroke. Since rebuilding older two-strokes seems to be the trend that’s currently sweeping through our sport, ARay’s interest was piqued and he gave us a call to see what we thought of the idea of buying the bike and building it up for the Red Bull Straight Rhythm in October, some five months away. With a ride on the HEP Suzuki team at the time, Ray was bound to a Suzuki RM250 as his only choice, and that made the $2000 price tag of the well-used machine all the more attractive. ARay asked if we would help him source out parts to rebuild the machine but we went one better and called out good friend Jay Clark from DirtBikeTV for an assist! In addition to running a great YouTube channel, Clark is a media representative for a bunch of great companies and an ace mechanic.

It’s a little-known fact that back home in Tennessee, Alex Ray’s family owns a successful pawnshop. Apparently, ARay’s pawnshop experience came into play and he successfully negotiated a lower $1300 price tag for the RM250. Score! When he got the 17-year-old RM250 home to his garage it miraculously fired up on the third kick and actually sounded kind of tangy. Against our better judgment, we took it out to Perris Raceway as is and Alex turned in some blistering laps aboard the clapped-out machine, which rode as if it had no fluids in the front or rear suspension components.

A few days later, we dropped the bike off at Clark’s home workshop and did what we could to help facilitate the rebuild. We dropped the stock Showa suspension components off at enzo racing and asked that they be rebuilt and set-up for Supercross. Mr brother Ross looked at me like I was an idiot when I told him ARay would be racing it at the Red Bull Straight Rhythm, and he told me that even back in their time, the Showa forks were impossible to set up properly for Supercross applications. That said, I asked him to valve them for ARay to ride motocross on, and then told Alex he needed to get to scouring Craig’s List for some suspension options. Remarkably, he found a set of Showa A-Kit suspension for an RM-Z250 for about the same price he paid for the bike and fell for the seller’s sales pitch that the stuff would bolt right on to the RM250 two-stroke. Haha! Fortunately, Scott Bennett at Showa saved the day when he agreed to replace the fork lugs with ones that would work, rebuild the forks for the RBSR, and supply a model-appropriate shock that was set up to match.

The master, Jay Clark, hard at work.

Though the RM250 seemed to run okay when Alex was ripping on it at Perris, we would take no chances. Jay tore into the engine and sent the cylinder and head to Tom Morgan at TMR for some added horsepower. Hot Rods supplied a rod rebuild kit, and the crank was rebuilt and balanced by the crew at Pro-Tec. When the cylinder and head were returned from TMR, Clark reassembled the powerplant with Cometic Gaskets and a Vertex Piston. A complete billet aluminum Hinson Racing clutch assembly was added to help put the power to the ground, and the engine’s intake and exhaust were completed with a Moto Tassinari V-Force Reed Cage and a FMF Racing Fatty Pipe and Shorty Silencer. 

Inside the RM250 powerplant lurks a Vertex Piston, a Hot Rods rod, and a crank that was rebuilt by Pro-Tec.

While the engine was out of the frame, Clark went over the chassis with a fine-tooth comb to check for cracks (the bike is, after all, 17 years old!), then sent it off to Chris Johnson at San Diego Powercoating for a high-gloss black finish. San Diego Powerdercoating is well versed in powder coating motocross bike frames and is hands-down, the best place on the West Coast to have a dirt bike frame treated. Concurrently, we disassembled the square stock wheels and sent the hubs to John Anderson at Dubya USA. Instead of going the expensive aftermarket hub route, Dubya USA offers a Cerakote service for the hubs that give them an awesome works finish. We opted for the brown magnesium color, but several options are available. Finally, the hubs were laced up to a set of flo-yellow Excel rims like the factory Suzuki team ran back in the day. Dubya USA’s wheel building team, by the way, is the best in the business at what they do.

Dubya USA’s Cerakote finish is affordable and awesome!

As far as the bearings and seals on the bike, most were replaced with kits from the guys at Pivot Works, which are available for all major component groups of a motorcycle and include everything you need for a project of this nature. While ordering stock parts would involve dozens of part numbers and the inevitable backorder, the Pivot Works kits are a one-stop solution. All Balls is a brand that makes excellent replacement cables and brake rebuild kits, so all of our controls were replaced and/or rebuilt to like-new performance. The old Suzuki front brake line used to wrap around the fork guard due to Honda’s old routing patent, so we utilized a shorter Galfer line to simplify the routing and improve the braking feel and strength.

Galfer brake components…it doesn’t get any better.

For the aesthetics of the bike, ARay and the SML team faced off on the bodywork. Alex liked the stock plastics and we liked the looks of the Polisport Restyle Body Kit, but since this was a Team Swapmoto Live machine our vote mattered most. Haha! The Polisport kit bolts right onto the old 2003 chassis and gives the bike a more modern look. Jared Hicks at Backyard Design USA designed and printed us a set of graphics for the machine, and Motoseat provided a matching cover.

We love the Polisport Restyle kit for the Suzuki as it gives the shroud a more aggressive look and replaces the massive old sidepanels with a cleaner, modern piece.

RIDING THE BEAUTY

On race day, Alex Ray’s pits filled with fans interested in the rebuild. ARay chronicled the build in his Vlog Life Series and tons of people stopped by to check it out in person. Well, it was either the bike or ARay’s annoying dog Johnny. Haha!

The RM250 or Johnny? You make the call…

Throughout the afternoon practice and qualifying sessions, ARay was competitive and quick aboard our project RM250 and he easily qualified for the 16-rider program at the Red Bull Straight Rhythm. Lining up and doing practice runs against the quickest riders in the field was fun, albeit discouraging depending on who you matched up against…

Doing practice runs against eventual event champion Ken Roczen made it pretty clear that our privateer build – though fun and enjoyable – was not up to par with the rebuilt factory bikes and modern-day Austrian machines.

As luck would have it, ARay was matched up against reigning Supercross Champion Cooper Webb in his first pairing, and our big effort at the 2019 Red Bull Straight Rhythm came to an abrupt end, not too long after the last note of the Star Spangled Banner was sung.

Alex Ray rode well and the bike ran great, but in the end were no match for Supercross Champion Cooper Webb and his factory KTM 300 SX.