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2008 Suzuki RM-Z450

2008 Suzuki RM-Z450

The 2008 RM-Z450 - The Winning Balance

Creating a champion doesn’t happen overnight. Developing a championship winning race bike could take a lifetime.  Being able to surpass both goals seems impossible, unless you are Suzuki.

Suzuki’s focus is building motocross bikes that win races – both for you at your local track and for Team Makita Suzuki’s Ricky Carmichael, the Greatest Racer of All Time. For 2008, Suzuki has narrowed that focus on the all-new RM-Z450, building off perfection to make this championship-winning motocross bike even better.

Suzuki knows that motocross racing is getting increasingly competitive, and the challenge to keep winning races and championships is what motivates Suzuki engineers to strive for perfection. Of course, championship-winning experience abounds at Suzuki. With a history of Lites-class championships or Carmichael’s more recent titles aboard the RM-Z450, Suzuki MX engineers have a great base to build from.

For even more title-winning experience, these engineers simply borrowed from Suzuki’s world-dominant GSX-R supersport team, pulling fuel-injection technology from the road circuit to the motocross track.

The all-new Suzuki RM-Z450 is the only motocross bike to deliver fuel injection – and Suzuki’s championship-winning fuel injection. Proven on Superbike road-race circuits around the world, and more recently in a championship-winning Suzuki LT-R450 motocross ATV, Suzuki fuel injection will raise the bar of performance in this highly competitive category.

As Suzuki engineers brainstormed the all-new RM-Z450, they focused on two goals. Creating a well-balanced motocross machine that encompasses high performance and flexible usability.
The all-new Suzuki RM-Z450 is locked and loaded to revolutionize the industry. For 2008, Suzuki developed the all-new RM-Z450 with electronic fuel injection for improved low-to-mid range throttle response along with a 5-speed transmission for smoother acceleration and increased riding flexibility. Combine all of this technology and innovation into an all-new well-balanced frame design creates the ultimate motocross weapon.

Engine Design

Fuel Injection

The concept is actually quite simple. Take championship proven fuel injection systems out of the Suzuki GSX-R and LT-R450 QuadRacer and apply to the all-new Suzuki RM-Z450. In order to meet strict motocross performance standards, Suzuki engineers designed the electronic fuel injection system to be battery-less. The result equates to improved “roll-on” power and a responsive low-to-mid range powerband keeping weight to a minimum.

Throttle Body

Balancing the right amount of air and fuel is the responsibility of the KEIHIN throttle body. Designed and produced by KEIHIN, it’s made specifically for the rigorous environment of motocross. The use of a progressive linkage at the throttle results in a more gradual opening at low throttle positions which Improves engine controllability and efficiency as it puts the power to the ground.

Fuel Pump

Enclosed inside a factory aluminum fuel tank, the KEHIEN fuel pump provides plenty of fuel pressure to operate the electronic fuel injection. The body of the fuel pump is enclosed within a rubber chamber while fuel is returned from the regulator to the lower part of the suction filter, creating a stable fuel supply.  Since fuel efficiency has been  increased, tank capacity has been reduced to 6.2 liters (1.6 U.S. Gallons).


The airbox is constructed as a separate unit which is sealed by a lid to prevent air leakage and improve overall intake efficiency.


Over the past years, Suzuki owners and factory racers voiced concern for a competitive transmission that would be flexible for winning races in all conditions. For 2008, the transmission has received an extra gear that all riders will appreciate. There’s no question that the 5-speed offers increased gear ratios for various terrains and conditions. With a link-type shifting system, the Suzuki RM-Z450 offers smooth transitions when clicking through gears. 

Whether you’re pounding out laps at the track or counting down miles on enduro loops, the Suzuki RM-Z450 5- speed transmission has you covered.


Since Suzuki engineers were inside improving and redesigning internal engine components, research and development went into increasing flywheel inertia. The results are a smoother revving engine, which improves the overall acceleration feel of the RM-Z450.

Cylinder Head (Intake Port and Intake Cams/Exhaust port,
Exhaust Cams and Exhaust Valves)

In order to fully take advantage of the all-new electronic fuel injection system, Suzuki engineers spent long hours in the dyno room and the computer lab improving cylinder head air velocity. The first step was changing the intake cam timing along with redesigning the intake port angle to reduce intake resistance, resulting in heightened intake efficiency to produce a linear, quick response. The second step was to optimize the exhaust port and cam timing to regulate exhaust pulses. Together the changes result in maximized engine performance. 

Combustion Chamber

While massaging the cylinder head internals, the combustion chamber shape received a make over with narrower intake and exhaust valve angles; moving to 11.5 degrees on the intake side and 10.0 degrees on the exhaust side. Along with geometry changes, side squish areas were increased for improved air/fuel mixing and faster flame- propagation speed when the mixture ignites, resulting in better power output and improved low-to-mid range response.

Chassis Design


An all-new frame design incorporates multiple changes learned throughout the racing season. Both tank rails and bracket body were reduced in size while the lower tube was enlarged to 30mm x 30mm making the RM-Z450 rail corners and blaze through whoops even faster. Overall frame weight has been reduced for more agile handling on various terrains.

Slim Riding Position

The development of the chassis focused on slimness while opening up the cockpit for additional room to allow the rider to actively take control of the machine.

Front Suspension

Inverted twin chamber SHOWA forks handle suspension needs up front. Various sections within the fork were modified to reduce weight and improve shock absorption. Design changes resulted in a better controlled feel and increased bottoming resistance. Front suspension modifications include: Weight Reduction-Reduced wall thickness on upper bracket, cut-away section between the outer-tube brackets extended, steering shaft press-fit section shortened, lower handlebar holder reduced in size, handlebar holder mounting rubber-section reduced in size.

Improved shock absorption-Rebound/Compression valve specifications optimized, main piston side-flow route expanded, rod pipe diameter widened, separator internal diameter widened, bush modified. Improved rigidity-Handlebar holder bracket made of castings

Rear Suspension

Covering the rear suspension is a SHOWA piggyback-reservoir shock that incorporates a newly designed damper case and modified internal structure. Design changes resulted in a better controlled feel and
increased bottoming resistance. Rear suspension modifications include: Weight Reduction- Rod neck shortened and reduced in size, chamber cap flanges wall thickness reduced.

Better Shock absorption- Damper case internal diameter’s precision increased, enlarged plug bolt diameter, rebound/compression valve specifications and characteristics optimized Rear Swingarm.

Rear Swingarm

To complement the RM-Z450 frame, Suzuki engineers designed a thinner wall thickness swingarm to reduce weight and improve terrain-traversing performance over bumps.

Electrical Design


Since Suzuki engineers focused on a battery-less fuel injection system, the all-new Suzuki RM-Z450 is equipped with a single-phase all-charging system with which the magneto supplies all of the necessary power. Switching from carburetion to electronic fuel injection requires an increased amount of data feedback for optimal levels of performance.

In previous years, a single-pin magneto did the job. However, implementing a high tech fuel delivery system requires an all-new 18-pin magneto to be designed. The 18-pin magneto senses feedback on crankshaft position, rotation speed and stroke which is fed back to the ECU to calculate optimum injection and ignition timings.

Styling Design

Unveiling one of the most exciting motocross bikes in history, Suzuki engineers went all the way with an all-new look while effectively utilizing wind flow dynamics.

Front Number Plate

An air-duct shaping that accentuates the front number plate design helps guide fresh air to the radiators for better cooling performance.

Front Fender

The front fender for 2008 incorporates a sloped-down shape to efficiently guide wind to the front number plate air ducts for improved cooling performance. 

Rear Fender

Finishing off the design of the all-new RM-Z450, air intakes are shaped on to both sides of the rear fender for heighten intake efficiency while tying in a fresh new look.

Radiator Shrouds and Louvers

New 2-tone molded-plastic radiator shrouds give the RM-Z450 a slim feel and stylish look for 2008 while also complimenting an all-new graphics design and colour-way. Redesigned outer louver plates offer better cooling performance by improving airflow to the radiators. 

Factory Race Team Hard Parts

Gold Chain

The factory gold-coloured chain adds the finishing touches to the bike.

Hot Starter

Adding to the factory touches, the hot starter has been relocated to the right hand side of the handlebar letting your left hand focus on operating the clutch in the time of need.

Disc Rotor

Helping the Suzuki RM-Z450 stop, race inspired wave disc rotors are bolted on the front and rear hubs. In addition to better cooling performance, wave disc rotors offer more efficiency slinging mud compared to traditional round disc rotors in muddy conditions. Front disc diameter: 250mm / Rear disc diameter: 240mm


Newly designed pegs include increased clearance between the mounting bracket and footrest to prevent mud from caking up.


The gripper seat has been improved this year by adding projected cross-shaped patterns on the top surface to provide additional grip.


Engine type: 4-stroke, liquid cooled, DOHC
Bore x stroke: 96.0mm x 62.1mm
Displacement: 449cm3
Compression ratio: 12.8:1
Fuel system: Kehin FI 43mm
Lubrication system: Suzuki Advanced Sump System
Clutch: Wet multi-plate type
Transmission: 5-speed constant mesh
Primary reduction ratio: 2.625
Final reduction ratio: 3.846
Front suspension: Showa 47mm telescopic forks, pneumatic / coil spring
Rear suspension: Swingarm, link type, Showa Piggyback – resevoir shock
Trail: 111mm
Front brake: Disc
Rear brake: Disc
Front tyre: 90/100-21
Rear tyre: 120/80-19
Overall length: 2,185mm
Overall width: 830mm
Overall height: 1,260mm
Wheelbase: 1,480mm
Ground clearance: 350mm
Seat height: 955mm
Dry weight: 101.5kg
Fuel tank capacity: 6.2L
Colours: Yellow only