First Look: 2008 Suzuki RM-Z Models

Suzuki announced their new 2008 models tonight at their dealer show at The Mirage in Las Vegas, and as expected, the '08 RM-Z450 was introduced as the first production MX bike that will feature electronic fuel injection. Suzuki already has ample fuel injection experience from their GSXR road bikes and LT-R quads, and they've tapped into that experience for this design.

So what's the buzz on fuel injection, and what does it mean for you? Simple. There's no jetting required. It's a system that self-compensates for temperature and altitude. It does require adjustment for humidity and specific terrains like a sand track, but a racing kit is planned, and will be built by Yoshimura. You can expect to see aftermarket control boxes like (Yoshimura's Cherry Bomb) that will allow easy plug-and-play adjustments for specific track conditions.

To answer a couple questions that we've seen on message boards, yes, the fuel tank will remain an aluminum piece in production. The tank is pressurized when the bike's running, the fuel pump is a Keihin unit that is specifically designed for the conditions and terrain unique to motocross. It mounts in the lower portion of the tank, and is removable for servicing. Because fuel will not flow while the bike is shut off, there's no need for a petcock, and the pre-production bike shown here isn't equipped with one.

There's allso no battery on the bike, or required for the fuel injection. It uses a single phase starting system...when the bike hasn't been used in a while, the first kick charges the capacitor. The second kick will have all the charge necessary to start the bike. After the bike has been ridden, and you shut it off (or stall in a corner), the capacitor is still charged, and according to the gang at Suzuki, it should fire right up.

The features and specs below are as current as we can get, but they may change before bike arrive at your dealer's.

You can click either of the photos below for a larger version.

RM-Z450
New Features

• Hot start lever is relocated to the right hand side of the handlebar for easy operation while holding the clutch.
• Race inspired wave-rotors provide better cooling performance and increased mud deflection in muddy conditions.
• Gripper seat has been improved this year by adding projected cross-shaped patterns on the top surface to provide additional grip.

New Engine

• Electronic Fuel Injection offers better roll on power and improved low-to-mid range power. KEIHIN throttle body specifically designed for motocross. Fuel is delivered via an internal fuel pump and is a battery-less system.
• 5-Speed Transmission makes the RM-Z450 more versatile for various terrains and features an all new link type shifting mechanism.
• Intake port angle and cam timing are revised and result in reduced intake resistance and heightened intake efficiency. Exhaust port and cam timing are designed to regulate exhaust pulses for maximum engine performance.
• Flywheel inertia increased to produce a smoother revving engine and improve overall acceleration feel.
• Airbox is constructed as a separate unit which is sealed by a lid to prevent air leakage and improve overall intake efficiency.
• KEIHIN fuel pump located inside the fuel tank provides stable pressure delivery to operate the fuel injection system.
• Redesigned combustion chamber for better power output and improved low-to-mid range response. Narrower intake and exhaust valve angle guides along with increased squish areas improve air/fuel mixing and faster flame-propagation speed when mixture ignites.
• Semi-dry-sump lubrication system features separate oil chambers for the transmission and crankshaft using the transmission as the oil sump, allowing low crankshaft placement, reduced engine height and a low center of gravity
• Battery-less fuel injection system features a single-phase all-charging system with which the magneto supplies all of the necessary power.
• 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.

New Chassis

• All-new frame is lighter and has improved rigidity balance for incredibly agile handling and unmatched performance over bumps.
• Slim riding position opens up the cockpit for additional room to allow the rider to actively take control of the machine.
• Showa cartridge-style front fork is fully adjustable for rebound, compression and preload settings and designed for reduced weight and improved shock absorption.
• Showa-brand rear shock absorber with a newly designed damper case and modified internal structure for a better controlled feel and increased bottoming resistance.
• Redesigned rear swing arm.Thinner wall thickness swingarm to reduce weight and improve terrain-traversing performance over bumps.
• Front number plate design helps guide fresh air to the radiators for better cooling performance.
• Front fender incorporates a sloped-down shape to efficiently guide wind to the front number plate air ducts for improved cooling performance. Rear fender incorporates air intakes on both sides for heighten intake efficiency while tying in a fresh new look.
• 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 color way.Redesigned outer louver plates offer better cooling performance by improving airflow to the radiators.
• Newly designed pegs include increased clearance between the mounting bracket and footrest to prevent mud from caking up.
• Gold-colored chain give a full factory look.

RM-Z450 Specifications

RM-Z250 Specifications

For you two-stroke lovers, the global brochure we received had the RM125 in it...but the bad news is, it's not destined for the U.S. market. The RM250 is still in the lineup, but has only received minor changes.