Gearing was versatile for all of the terrain we encountered with first gear being short enough to allow for uphill launches from a dead stop
"You're not supposed to have this much fun on a quad," I thought as I counter-steered through the apex of a dusty off-camber turn. As I dial in more throttle, the engine responds instantly, putting more spin back to the rear tires. The tires answer by flinging even more earth into the sky as the rear-end continues to drift to the outside. I grab an upshift; only then do the tires begin finding traction and come back inline. Sounds fun right? It is, and its just one of the many amusing experiences you'll have aboard Suzuki's updated QuadSport Z400
Despite only being around for six years, the Z400 has developed a reputation in the ATV world thanks to its unique pairing of a powerful yet easy-to-use liquid-cooled engine and a versatile chassis that's at home on any type of terrain. But for 2009, engineers wanted to inject some DNA from its competition-oriented brother, the QuadRacer R450
, for even more performance while retaining its all-around sporting talent.
The heart of the Z400 is the same liquid-cooled 398cc 4-stroke Single that we've come to love, only this time it's fuel-injected, which almost guarantees a clean running machine regardless of atmospheric conditions or altitude. A new 12-hole Keihin fuel-injector sucks fuel down from the 2.5-gallon fuel tank and squirts it into a 36mm throttle body. Powering the setup is a sophisticated new ECU which monitors throttle position, engine RPM, and intake air pressure to determine optimum fueling and ignition timing. The ECU also selects from one of four individual injection mappings ensuring proper carburetion under any conditions.
Although the engine's 4-valve DOHC architecture remains the same, the intake port is now smaller in diameter and has been placed at a straighter angle for increased power down low. The camshaft profile and timing have also been revised in the name of improved bottom-end power. Additionally, the exhaust system received a couple of tweaks: the header pipe has been shortened to retain high rpm performance, while the muffler itself has been shortened and its internal construction altered to go along with the subtle tweaks on the intake side.
Keeping the engine properly oiled is a dry-sump engine lubrication system that eliminates the need for a conventional oil pan, thereby reducing engine height and allowing for a smaller crankcase. A large radiator and temperature-controlled cooling fan ensure that the engine is always the right temperature regardless if you're riding in a desert inferno or snow capped mountains.
Externally, it can be hard to distinguish the Z400 from the R450 as it sports a new look that closely resembles that of Suzuki's flagship sport ATV. At the front, a much more aggressive-looking snout extends forward with a detachable 40W halogen headlight. Straight-cut fenders match the edgy design of the front and give it a much more streamlined look than before.
Modifications to the upper and lower A-arms further enhance stability and control by widening the front track to 960mm (up from 935mm).
Underneath the sharp-looking plastics is a revised chassis engineered to give riders more control while still providing a high-level of comfort out on the trail. The frame itself is still constructed out of steel but incorporates a number of clever modifications aimed at increasing overall rigidity and balance. Tank rail tube wall thickness was increased by 0.4mm, while the pivot section bracket shape was changed. The rear shock mounting tube and the shock link mounting section are now thicker. And the rear brake master cylinder has been moved from the seat rail to the frame down tube. The removable steel subframe has also been reworked and is made out of rectangular tubes for increased rigidity just like the R450.
Modifications to the upper and lower A-arms further enhance stability and control by widening the front track to 960mm (up from 935mm). However, widening the track can compromise steering, so engineers decreased the caster by 2.2-degrees (from 8.5-degrees) as well as decreasing trail by 7mm (from 36mm). Camber was also changed and has been toed inwards by 1.5 degrees, all to ensure light steering feel.
Handling suspension duties up front are dual remote-reservoir equipped coil-over shocks that are adjustable for preload and compression. The shocks feature revised damping characteristics that offer 43% less preload resulting in greater plushness at the top of the stroke, yet still retain good bottoming resistance as the shock nears its maximum 8.5-inches of travel. Out back, a single fully adjustable (preload, compression and rebound) reservoirâ€“equipped coil-over shock offers 9.1-inches of travel and manages the beautifully machined aluminum swingarm. Ground clearance is a plentiful 10.4 inches.
Climbing aboard the Z400 reveals a comfortable, supportive T-shaped saddle, but it is an ever-so slightly cramped riding position for my 6-foot frame. Although engineers moved the handlebar position forward by 10mm they also moved it lower (5mm) making it that much more of a stretch - especially when standing up. Fortunately all it takes is a quick handlebar swap and us non-vertically challenged riders will be good to go. Conversely, change in the footpeg position (5mm lower and 2mm back) worked well for us and offered our lower extremities plenty of room to move around freely, especially when flinging your body from side-to-side during cornering.
Throttle response is precise and immediate at any engine speed and unlike other bland 'electric' feeling FI-equipped machines we've ridden, the Z400's engine retains a unique character that makes exploring its powerband fun and exciting.
Starting the QuadSport is as easy as a turn of the key and a thumb of the starter button (which you can do in-gear). A manual fast-idle lever is also present, but we question why its use would ever be required since the engine is fuel-injected. A cable-actuated clutch manages the five-speed transmission (with reverse) and clutch lever pull is exceptionally light and engagement is progressive. Gearing was versatile for all of the terrain we encountered with first gear being short enough to allow for uphill launches from a dead stop and fifth gear on the taller side ensuring a high top-speed on open fire-roads. Using reverse is as easy as turning the right-hand side fender knob while pressing all the way down on the shift lever.
Even though the Z400 weights in at a claimed 425 pounds, the engine has plenty of muscle to propel it forward. Considering it's pushing around that much weight, power is astounding, really, with a hearty bottom-end punch that seamlessly transitions throughout the rev range. There is plenty of snap to loft the front wheels in the first three gears, yet it never feels intimidating or uncontrollable. In fact the only real flaw we can find is that power signs off a bit early on top-end. But as long as you're quick with the upshifts, it's not that much of an issue.
Suzuki was one of the first companies to pioneer fuel-injection on its sport motorcycles and ATVs (1998 GSX-R750, 2005 KingQuad 700) so it comes as no surprise that the system on the Z400 is well sorted. Throttle response is precise and immediate at any engine speed and unlike other bland 'electric' feeling FI-equipped machines we've ridden, the Z400's engine retains a unique character that makes exploring its powerband fun and exciting.
We had the rare opportunity to ride at Vessels Stallion Ranch
, near Oceanside, California, which provided a variety of different trails that included some rough hill-climbs, fast off-camber bends, and tight twisty pathways which provided a good variety of terrain in which to evaluate Suzuki's chassis upgrades. One of the things most apparent is just how easily it changes direction. All it takes is a simple nudge of the handlebars and blip of the gas. The sharper handling is complemented by the grippy Dunlop radial tires and the extra-wide 46mm footpegs provide a stable base to position your body during cornering. Overall stability and balance front-to-rear is also a strong point of the Z400, and the quad remained planted most of the time. When it would go on two wheels, it felt neutral and is easy to correct. In most of the conditions we encountered, the suspension delivered a comfortable ride. Action was very plush initially, but on some of the rougher segments it would quickly get out of shape and begin to dictate the direction where the quad would go. However, bottoming resistance is good with the suspension very capable of absorbing landings off of smaller jumps.
We had the rare opportunity to ride at Vessels Stallion Ranch, near Oceanside, California, which provided a variety of different trails that included some rough hill-climbs, fast off-camber bends, and tight twisty pathways which provided a good variety of terrain in which to evaluate Suzuki's chassis.
Braking duties are handled up front by dual 6.9-inch hydraulic single-piston disc brakes. Just like the LT-R450, an adjustable front brake lever is utilized to accommodate different hand sizes. Front brake pad material has also been updated and has a 10% higher coefficient of friction. Controlling the rear wheels is a 8.6-inch single disc brake that shares the same caliper body as the QuadRacer but utilizes a different brake pad material. The rear brake pedal shaft length has been increased in efforts to increase feel.
Although outright braking power provided by the front brakes isn't that impressive, you can still use them aggressively because they have a good amount of feel. Contrarily, the rear setup is fantastic with an almost perfect amount of power and feel.
I'm not going to lie; I'm a die-hard motorcycle guy. But Suzuki's updated QuadSport impressed me so much that now I'm thinking that four-wheels might be the way to go. It's easy-to-ride for a beginner yet still provides a high level of performance for a hard-core enthusiast. And for its $6199 asking price, you get a whole lot of machine for your money. Maybe four wheels aren't so bad after all.
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