The Kawasaki KFX450R is Kawasaki’s first foray into the 450cc sport quad market. Rather than follow in their competitor’s footsteps, Kawasaki decided to blaze their own trail, and innovate where they could. An aluminum chassis, electric start, reverse, and Digital Fuel Injection are just a few of the features that grace the KFX. The end result is a formidable, lightweight machine, with plenty of competitive potential.

Engine The KFX450R’s liquid-cooled, DOHC, four-valve, four-stroke single cylinder powerplant, is based on the highly acclaimed KX450F motocross engine. The 32-bit digitally fuel injected (DFI) motor is not only efficient, but extremely responsive, thanks in part to the 42mm throttle body. The DFI automatically compensates for just about any conditions by measuring coolant & air intake temperatures, air intake pressure, engine speed, and throttle position. DFI basically translates to perfect jetting despite temperature, or altitude. A nice side effect of the Fuel injection is that it allows the use of a lighter throttle return spring, which greatly reduces thumb fatigue.

From a technical standpoint, the motor is state of the art. For starters, the piston uses three rings (as opposed to two), and a larger (21mm) piston pin, which combined greatly reduce the necessary maintenance, and increase reliability. Asymmetrical, high-acceleration cams increase intake efficiency, and titanium valves and aluminum valve spring retainers lower the reciprocating weight while boosting high-rpm reliability. Even the airbox is designed to increase the intake efficiency, and sharpen engine response due to its large volume.

Transmission-wise, the Kawi’s five-speed manual tranny, is flawless. The stock gearing is fine for just about any conditions, and the convenient reverse comes in handy whether riding for fun, or in the midst of a misstep during competition.

While not the torquey-ist of the 450s on the market, the KFX’s power is among the most useable. The motor is simply well thought out, and while features like reverse, DFI, and a titanium header pipe may not seem like “must haves”, they can make the difference between a simply good time, and a great one while out riding.

Chassis, Suspension, & Brakes Built with tough trail conditions, and race wins in mind, the KFX’s innovative, lightweight, all-aluminum frame is both incredibly stiff, and significantly strong. The high-tech chassis provides a low center of gravity, and great roll resistance, allowing the rider to corner faster, and more securely. The battery, and coolant tank are both mounted ahead of the engine, which in turn lowers the center of gravity, and helps shift weight towards the front wheels for increased traction. The single box-tube lower frame contains the front A-arm attachment points. The narrow design actually allows the use of longer lower A-arms, and longer travel suspension.

Speaking of suspension, the front shocks are paired with dual-rate springs, which offer progressive travel, and soak up everything from stutter bumps, to decent sized hits well. The narrow overall width of the machine (46.1”) makes it better suited for tight trails, than full-blown Motocross tracks. The rear shock is low, and high-speed compression adjustable, as well as rebound damping adjustable, and is mated to a cast aluminum swingarm. The rear suspension package offers a decent balance of flexibility and rigidity. The curved lines, and rounded edges of the cast aluminum rear swingarm were designed to help disperse stress. In addition, the swingarm’s varied wall thicknesses help complete a design that is both strong, and light.

Dual 163mm front hydraulic disc brakes offer strong, consistent stopping performance thanks to the two-piston calipers. The KFX’s front brakes are on par with most 450s in its’ class, while they don’t stand out as the greatest, they’re certainly among the best. The rear brake is a 200mm petal-type rotor with a single-piston caliper. The petal-type rotor reduces unsprung weight, and helps keep the brake pads clean for more efficient braking performance.

Ergonomics Ergonomically the KFX450 is a comfortable machine. The controls are in the standard locations, functional, and easily reachable. No control requires awkward movements, or too much thought. The levers, and perches are the norm for a 450cc sport quad; the only difference is the reverse, which most other models lack. In order to actuate the reverse gear, you must shift down past Neutral while simultaneously pushing the lever with your right thumb. It sounds more complicated than it is, and once you get used to it, becomes second nature. The seat is comfortable, and features a smooth top surface, and slip-resistant sides for added grip. The “gripper” sides make hanging off of the machine while cornering a breeze. The tank width makes it easy to move around, while riding, and doesn’t hamper you in situations where you need to shift your weight forward. Tapered Renthal Fatbars are standard equipment, as are “fat bar” clamps, which make selecting a good replacement bar bend a breeze, as you won’t have to purchase a “fat bar” clamp.

The KFX450R is easy to work on, so owners can spend more time in the dirt than in the garage. The two-piece front and rear “lapped” fenders make it easier to customize the size of the fenders or quickly replace damaged sections. Even the headlight assembly is quickly detachable for closed-course races—this ATV looks just as aggressive with or without headlights. These features leave little doubt that the KFX450R was designed to be on the track and winning races as quickly as possible. The stock 20” tires are great for sportier trail rides, and would work in most beginner MX applications. The rear wheels are equipped with reinforcing plates for added strength, located on the axle side of the rims, the plates reinforce the wheels where most needed, without adding excessive weight. The lights work well, and are easily removable for racing applications, as are the outer edges of the stock plastic.

Overall the Kawasaki KFX450R is one of the best ATVs with a solid, lightweight platform on which to build your next race machine, or rec ride. Kawasaki’s innovations when it comes to weight savings are admirable, and pound for pound the KFX is hard to beat.