2021 Suzuki RM-Z250

Advanced Electronics

• Included with the 2021 RM-Z250 is Suzuki’s MX-Tuner 2.0 that provides the ability to easily adjust the fuel injection and ignition system settings for optional race performance. Using a smartphone application that wirelessly connects to the MX-Tuner’s compact transceiver, fuel delivery and ignition timing can be quickly changed. The MX-Tuner application can pre-program personalized settings into the ECM that can be activated by plugging in one of the supplied fuel couplers. Racers and tuners can easily change settings to match performance-related updates. The application can save a number of settings for different tracks or weather conditions, plus settings can be exchanged with other racers. Real-time engine data and run-time information are accessible to help you stay on top of bike maintenance.
• Suzuki’s proven, easy-to-use fuel couplers are also included to simplify EFI tuning. For quick fuel adjustments to suit riding conditions, two couplers are provided. One is for a richer-than-stock and another for a leaner-than-stock fuel setting. Riders can change fuel settings in seconds by simply connecting either coupler to the wire harness.
• The RM-Z250 features an evolved and faster traction management system that reacts to engine speed changes quickly. The Electronic Control Module (ECM) continually measures throttle opening, engine speed, and gear position, and then adjusts the ignition timing and fuel injector duration to fine-tune the engine output to deliver the best traction for the riding conditions. The RM-Z250’s traction management system is different from a street bike traction control system, as it does not measure rear tire spin. Because the needs of a motocrosser are different than a street bike, this system offers constant adjustment that maximizes traction at all times.
• The Suzuki Holeshot Assist Control (S-HAC) is a selectable launch system derived from the factory race bike to help riders’ takeoff from the starting gate for an early lead. To aid riders at the moment of launch, there are three stages of power adjustment from the S-HAC system: 1) the moment of initial launch, 2) when crossing the starting gate, and 3) acceleration up to full-speed.
• There are three S-HAC modes riders can choose for the best option per their skill level and starting conditions.
• Mode A: For hard surfaces or slippery conditions at the starting gate. In this mode, S-HAC alters ignition timing at the moment of launch and the ride over the gate to reduce wheel slip to deliver a smooth takeoff. It also advances ignition timing during this sequence for stronger acceleration. After six seconds or when you reach fourth gear, the system shuts off and returns to normal ignition timing. Benefit of Mode A: For novice riders, and/or hard and slippery traction conditions, use Mode A for a more controlled launch.
• Mode B: When conditions at the starting gate have better traction, and a more aggressive launch is desired. S-HAC will advance the ignition timing to allow increased throttle response and stronger acceleration off the line. The ignition timing alternation is in a similar sequence as Mode A, but with increased overall timing. One of three conditions will return the ignition to normal operation (whichever happens first): After six seconds or when you reach fourth gear, the system shuts off and returns to normal ignition timing. Benefit of Mode B: For skilled riders, and/or good starting conditions, use Mode B for a more aggressive launch.
• Base Mode: Standard power launch, no action required on the S-HAC switch.

Chassis Features

• The RM-Z250 features a frame and swingarm design that continues Suzuki’s reputation for creating the best-handling motocross motorcycles.
• The aluminum alloy, twin-spar frame combines cast and extruded sections to achieve superior front-and-rear weight distribution, while balancing strength and weight.
• The 2021 RM-Z250 frame is 370 grams (0.8 pounds) lighter but has a 10 percent increase in torsional rigidity as compared to the prior generation frame.
• The engine's position in the frame is rotated up so the crankshaft sits higher in the chassis to further the bike’s nimble handling characteristics.
• The rear, upper engine mounts are outboard of the cylinder head to increase rigidity and allow a direct intake path to the engine.
• The engine mount material is changed to aluminum, rather than steel, for reduced weight.
• The swingarm is shaped using an innovative hydroforming process that maintains strength but weighs 0.6 pounds (270 grams).
• The hydroforming process enabled engineers to create tapered swingarm beams that increased rigidity, while reducing heavier assembly welding.
• Hexagonal aluminum rails are used on the sub-frame for lighter weight, a slimmer appearance, and easier air filter access.
• The sub-frame rails are moved inward to slim the bodywork but are also raised to provide additional space for the larger air cleaner.
• Not only is the new sub-frame narrow, but all of the body work is slim, so the rider can move freely in the cockpit, especially during spirited riding.
• The KYB-supplied shock absorber has a thin-wire spring, spring guide, cushion rubber guide, and lower link that are lightweight and have better movement reaction. The spring and link weigh a pound (447.5 grams) less than the prior generation's parts.
• This KYB shock has specialized damping force circuits and a refined rear lever ratio to help improve the suspension’s traction characteristics.
• The damping force adjusters have a wide tuning range, so the settings can better match the conditions and the rider’s style.
• The high-performance KYB coil spring front fork has legs with the same springs and damping force components, so front suspension tuning and maintenance is balanced and easy: a great benefit during frequent riding.
• This fork uses a free-piston design that separates air and oil to optimize the damping characteristics. The design also helps control the damping cartridge’s pressure and spring recoil, so the fork action remains supple and precise.
• The Renthal aluminum tapered handlebar has a flatter bend with less pull-back than prior models to aid rider control during aggressive maneuvering.
• A rigid, but lightweight upper fork bracket complements the front suspension and handlebars.
• To improve stopping performance and feel, a 270mm diameter, wave-style front brake rotor and a Nissin two-piston brake caliper are used.
• The brake pad material was developed for the RM-Z250 to improve performance. The master cylinder is a push rod type that more effectively transmits the squeezing force that the rider applies to the lever.
• The rear brake master cylinder hugs the frame beam to reduce dirt contamination and the chance of the rider’s boot touching it during riding.
• The wheels feature black anodized D.I.D Dirt Star rims with a cross-section design that maintains strength while reducing un-sprung weight.
• To match the handling potential of the RM-Z250, the wheels are fitted with racetrack-developed Dunlop Geomax MX33. Additionally, the rear tire is nearly a half-pound (160 kg) lighter than the tire used on the prior generation RM-Z250.
• Suzuki beak-inspired styling has a sharp front fender and radiator shroud shapes that blend into the frame’s side covers and an upswept tail, to promote the impression of speed while reducing weight and easing service.
• The functional styling and the motorcycle’s trim chassis permits a variety of rider positions that facilitate control and comfort.
• Compared to the prior RM-Z250, the 2021 edition has ergonomic improvements from the new bodywork, the rider’s footpegs are moved 0.12 inches (3.3 mm) forward and 0.2 inches (5.2 mm) upward, while the handlebar grip position is moved 0.3 inches (7.4 mm) forward and 0.15 inches (3.8 mm) downward, to create a high level of rider-control during competition.
• The plastic fuel tank weighs a half-pound less than the prior model’s aluminum tank. Fuel capacity is 1.66 US gallons.
• The seat base, inner fenders, and side covers were developed to reduce moisture and dirt from reaching the air cleaner. This helps prevent debris from contaminating the air filter.
• The slimmer seat has a specialized foam density to aid the rider’s control of the motorcycle. The seat has a large gripper panel that runs nose-to-tail on the cover.
• The Suzuki Champion Yellow bodywork is enhanced with distinctive striping and modern logo graphics that are updated for 2021.

Engine Features

• Fitted with a center-port cylinder head, the fuel-injected, 249cc, liquid-cooled, four-stroke, four-valve, DOHC engine remains proven and reliable.
• The engine delivers strong peak power and superb throttle response through the entire rev range.
• The cylinder head features a refined intake port shape and finish that fine-tunes the fuel/air charge into the combustion chamber to increase engine output.
• A large air cleaner opening is combined with a more direct air cleaner outlet tube path into the throttle body for high-volume air flow.
• The fuel injection system has extra-smooth power delivery, high fuel efficiency, superb reliability, and easy tuning capability.
• First introduced on the RM-Z250, twin fuel injectors are used to deliver excellent combustion chamber efficiency and increases high rpm power.
• The primary fuel injector is at the bottom of the throttle body and sprays fuel at the butterfly valve for outstanding fuel and air atomization. The secondary injector is positioned in the air cleaner inlet duct so the fuel and air have more time to mix and cool before entering the engine.
• To feed the new twin-injector system and mix the fuel and air charge for outstanding throttle response, the RM-Z250 uses a high-capacity fuel pump.
• The special design of the throttle body eliminates complex control linkage, so the rider feels a more direct connection to the engine.
• The intake camshaft profile has more valve lift that the prior generation RM-Z250, increasing power at all engine speeds.
• The cam chain tension adjuster and guide have been designed to reduce friction and mechanical loss.
• The compact aluminum cylinder is finished with Suzuki Composite Electrochemical Material (SCEM) coating for durability, light weight, and efficient heat transfer.
• The machining process at the piston pin holes is changed to reduce stress at the piston crown to increase reliability.
• Engine starting remains simple, due to a proven kickstarter and automatic decompression system that works precisely and efficiently (eliminating the need for a heavy and costly electric start system).
• The high-flow exhaust system has a longer head-pipe, tapered mid-section, and multi-layer silencer with good flow through the entire rev range, with an emphasis on low-rpm performance.
• The exhaust silencer is a four-layer design that enhances performance and maintains compliance with AMA sound regulations.
• The resin engine protectors help guard the coolant pump (on the right) and the stator cover (on the left) from debris and stones.

Key Features

• Superb Engine Performance. Center-port cylinder head increases output and throttle response, Dual fuel injector system boosts high rpm power, Traction management system helps the bike hook up, Suzuki Holeshot Assist Control (S-HAC) gets you out front.
• Exceptional Cornering Performance. Frame and swingarm balances lightness with strength, Engine placement and mounting aid chassis' nimble handling, Coil spring KYB fork provides outstanding performance and easy tuning, KYB rear shock and linkage deliver remarkable control, Race-ready, high-grip Dunlop MX33 tires.
• Controlled Braking Performance. Large-diameter front brake increases stopping power and feel, Compact rear master cylinder is designed to prevent mud from collecting on it and from catching on the rider’s boots.
• Functional Styling. Aggressive new styling from the championship caliber RM-Z450, Narrow cockpit lets rider move with ease for maximum racing performance.
• Rider-friendly Tuning. Suzuki’s MX-Tuner 2.0 is supplied, providing quick fuel injection and ignition tuning through an easy-to-use smart-phone application, Fuel couplers are also included for quick and easy EFI tuning.

Transmission & Drive Features

• The five-speed transmission's second gear ratio and overall final ratio matches the engine’s stronger output for outstanding acceleration and top speed.
• True to Suzuki transmission standards, the gear shift operation is smooth and precise. Carefully designed parts like the precisely machined shift cam and corresponding gears create a transmission a racer can rely on.
• The multi-plate, wet-clutch uses a rack-and-pinion clutch release mechanism for precise feel of the engagement and disengagement points while riding.
• The lightweight chain guide is shaped to accurately route the drive chain smoothly.