The QuadSport Z400 fires up, in any gear, with the push of a button. Its liquid-cooled, 398cc, four-stroke single is electronically fuel-injected (EFI), and starts right up in just about any altitude or temperature. The EFI is run via an ECU brain that tells the Keihin fuel injector to pump fuel to its 36mm throttle body. The ECU monitors throttle position, engine rpm and intake air pressure to determine optimum fueling and ignition timing and selects from one of four injection mappings ensuring proper carburetion under any conditions.
A reliable, five-speed transmission is operated by an easy-pull clutch lever, which gets the power to the rear wheels. Plus, the Z has reverse, which is a very valuable asset on tight trails. Pull in the clutch, twist the knob on the right-hand side of the front fender and you’re backing into your riding partner. We rarely needed to use the short first gear. We took off from second gear at times, and used it to lug around at slower speeds. Its top speed of 50-plus isn’t overwhelming, but it will still get you down fire roads in a hurry. Install an aftermarket exhaust, remove the airbox lid and put in a more open filter and you will see the numbers increase a few digits.
The fuel injection provided the QuadSport with very smooth power delivery through the ranges. The throttle is easy on the thumb on longer rides, and the throttle response is excellent! If you stabbed the throttle, the front end would almost immediately pop up. If you stay smooth on the throttle, the front end won’t lift, and you’re off in a hurry. The first three gears have a surprising amount of torque and transition smoothly through fifth gear. That poppy front end makes it easy hopping over tree stumps and carrying the front end through rough terrain.Suspension, Treads And Stopping Power
The QuadSport provides a plush ride all around. Up front is double A-arm suspension that offers 8.5 inches of wheel travel. It is equipped with dual-remote, piggyback-reservoir shocks that are adjustable for preload and compression. It’s matched at the rear by a machined aluminum swingarm and linkage-type suspension that offers 9.1 inches of travel and a fully adjustable shock.The Z400 is precise and predictable on the trails. The suspension soaks up every bump, jump and choppy terrain. You can feel the rough obstacles through the suspension, but it never seemed to be too harsh of a ride. Although it weighs over 400 pounds, the Z400 has a lightweight feel that makes it easy to maneuver all day long. It also flies straight and flicks around in the air.Riding on the suspension is a lightweight aluminum wheel and Dunlop radial setup. The fronts are 10x5.5, and the rears are a 9x8-inch setup. The tires are tough and hooked up well in the hardpack and loose sandy trails.Braking power on the Z400 matches the chassis well. In the front are 6.9-inch discs, and in the rear is an 8.6-inch single disc. The front brake lever has an adjustable position mechanism, and the single rear disc brake shares the same caliper body as the QuadRacer 450. The brakes are awesome on downhill descents. Some sport machines have touchy braking, but the Z’s seemed to have a good feel when you needed it.

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Spec Chart2012 SuzukiEngine
Type: 4-stroke, single-cylinder, DOHC
Displacement: 398cc
Bore x stroke: 90.0x62.6mm
Cooling: Liquid-cooled
Fuel system: Fuel injection with 36mm throttle body
Starting system: ElectricDrivetrain
Drive system: 520 chain
Transmission: 5-speed with reverseSuspension (Type/Travel)
Front: Dual A-arms/8.5 in.
Rear: Swingarm/9.1 in.Tires
Front: AT22x7R10
Rear: AT20x10R9Brakes
Front: Dual discs
Rear: Single discDimensions
Wheelbase: 49.0 in.
Claimed curb weight: 425 lb
Ground clearance: 10.4 in.
Length/width/height: 72.0/46.9/31.9 in.
Seat height: 31.9 in.
Fuel capacity: 2.4 gal.Electrical
Lighting: Detachable 40-watt halogen headlight
Colors: Green/black, white