The Ultimate Form of Yoshimura’s Latest Custom: KAWASAKI Z900RS Custom by YOSHIMURA

YOSHIMURA's Z900RS

In 2024, YOSHIMURA celebrated their 70th anniversary. More than just a pillar of the global racing scene, YOSHIMURA has also been a pioneer in the custom world, using their racing know-how to develop and sell both performance parts and complete machines. Today, the Z900RS/CAFE is one of their main targets for street-oriented products.

Since the bike’s debut at the end of 2017, YOSHIMURA has steadily rolled out parts for it. In July 2021, the company launched the Z900RS/CAFE YOSHIMURA Heritage Kit AMA Edition, a bodywork kit paying homage to the YOSHIMURA Z1 that competed in the 1976 AMA Superbike Championship. The lineup included SPEC 1, a set centered on exterior parts and still available to order today, as well as SPEC 2, which added a special exhaust, rearsets, and a radiator core guard, though this higher-grade version has already sold out.

The machine shown here is based on the SPEC 1, but with further updates: front and rear suspensions, brake discs, wheels, tires, intake and exhaust modifications, and fuel mapping adjustments. In other words, it’s an evolved version of the YOSHIMURA Heritage Kit AMA Edition SPEC 1.

All parts are bolt-on, including those affecting intake, with each area carefully set up. The result is more feedback from the bike to the rider, especially through the tires. For example, output response to throttle input is not only linear but also smooth, making it easier to open the throttle. Throttle and brake inputs generate slightly more pronounced pitching, giving the rider time and space to anticipate and prepare their next move.

This makes the bike’s responses and behavior clearer, though it diminishes some of the positive ambiguity built into the stock setup. This is a feature unique to customization, where the rider decides what to prioritize. Settings can be adjusted, so there’s still flexibility to fine-tune this balance.

The YOSHIMURA Z1 is a legendary model that made a huge impact in AMA Superbike and cemented the reputation of Japanese four-cylinder bikes. Even the SPEC 1 kit alone can capture that essence and reflect it in the Z900RS/CAFE. Riders can simply enjoy the look, or use this build as a reference to collect parts and bring their bike's characteristics closer to the real thing.

Handlebar

The stem is the stock Z900RS, fitted with YOSHIMURA parts such as the handlebar clamp, bar ends, brake lever guard, grip rubbers, and the PRO-GRESS2 multi-temp meter. The foldable brake and clutch levers are ZETA Pilot levers.

Bodywork

The “Z900RS/CAFE YOSHIMURA Heritage Kit AMA Edition SPEC 1” is made up of a fuel tank and seat cowl painted to recreate the look of the 1976 YOSHIMURA air-cooled Z racer, carbon side covers and front fender, a crankcase emblem set, and a reservoir tank band. The SPEC 2, with a limited production of 50 sets, has already sold out and production has ended.

Engine

The engine itself remains stock, but it is equipped with the YOSHIMURA racing slider kit “PRO SHIELD,” machined aluminum frame caps, and a radiator core protector. Inside the air cleaner box, a TMS funnel kit has been installed.

Intake & Exhaust

For the exhaust, the bike uses a 4-2-1 YOSHIMURA Straight Cyclone Duplex Shooter with a matte black finish. The one shown in the photo, the “Hand-Bent Straight Cyclone Duplex Shooter,” uses hand-bent steel pipes with stainless steel after the collector. There is also the “Machine-Bent Straight Cyclone Duplex Shooter,” which is entirely stainless steel.

The Straight Cyclone Duplex Shooter combines the look of classic short pipes with modern performance by incorporating a sub-silencer under the swingarm pivot. The photo is taken from slightly behind on the left side of the bike, and it blends in without looking out of place.

Chassis

The YOSHIMURA Rearsets Kit X-TREAD allows the bar position to be set in four ways: 45 x 40, 45 x 55, 57.5 x 40, and 57.5 x 55 (back x up, mm). The pedal positions can be selected in two ways on the brake side and three ways on the shift side. This machine is also equipped with a BAZZAZ quickshifter.

The front forks are the stock 41mm inverted type, fitted internally with an Ohlins FKS511 cartridge kit (NIX30 Street, with compression damping on the left and rebound damping on the right). The front brake discs are SUNSTAR Premium Racing Discs.

The rear shock has been replaced with an Ohlins KA739. The carbon side covers are those from the Heritage Kit.

The swingarm and rear brake caliper are stock Z900RS, while the rear brake disc is a SUNSTAR Premium Racing Disc. The front and rear wheels are ThyssenKrupp dry carbon, with BRIDGESTONE S23 tires in 120/70ZR17 and 180/55ZR17 sizes.

Gallery

Specifications

About YOSHIMURA

YOSHIMURA has conducted research and development in motorcycle parts and participated in races for years. Users extremely support their product performance and craftsmanship created from their high technology.

YOSHIMURA brand page

Original Source of this Article

Heritage & Legends