2010 Kawasaki KFX450R Review

Rick Sosebee
by Rick Sosebee
We test Kawasaki's mean, green racing machine

The sport segment has long been a testament to the manufacturers’ ability to keep up with changing trends in the ATV market and the 2010 KFX450R is Kawasaki’s shot at the bull’s eye.

Simply stated, Kawasaki has built a race ready and motocross friendly ATV that can be prepped with little more than fuel and a clean air filter before being dropped onto the starting grid. From the technology in the frame to the power ripping through the exhaust the Kawasaki KFX450R has made its statement on the sport ATV market. Just in case you’ve forgotten, let us refresh your memory.

Starting with the frame we notice several key items that seem to bring Kawsaki into the game of MX/XC ATV racing. It seems that Kawasaki has taken notice of aftermarket 250r frames. More rake and better steering and handling geometry is what most guess is the benefit of having the lower A-arms come together in the middle of the lower frame.

Kawasaki’s light and rigid frame gives the rider impressive control while cornering.

Kawasaki’s light and rigid frame gives the rider impressive control while cornering.

The frame is all aluminum and only weighs in at 26 pounds – about 20 percent lighter than the competition. The framework is ultra rigid and this ensures the quad has little roll while cornering. The anti-dive technology built into the frame keeps the chassis very level under hard braking into corners without sacrificing suspension feel to the rider.

The 449cc engine provides ample low-end torque to help get racers off the line in an hurry.

The 449cc engine provides ample low-end torque to help get racers off the line in an hurry.

The motor in the KFX450R was derived from the MX side of Kawasaki’s race breed. The powerplant produces massive amounts of torque in the low and mid range, which should drive racers to the front off the start and hold together for the long haul. The engine breathes in through the Keihin 42mm throttle body fuel injection system that is becoming quite popular in off-road machines. Fuel injection not only allows the engine to start and respond quickly but the use of a choke for bringing the engine to life is no longer needed.

Compression ratio in the KFX450R is 12:1 and there are two preset rev limits. The motor will turn up to 10,500 for the stage one preset and then to 11,000 for the second. These RPMs are courtesy of a two-piece balancer that helps reduce vibration. The engine comes to life via an electric start or there is a kick-start available as an accessory. The injector in this 449cc propulsion unit is a ten-hole injector for an ultra fine pattern, which helps provide a complete burn in the cylinder. This just means extra excitement for the rider. Unlike the competition the KFX450R will require high-octane pump gas to run properly, so trail warriors will have to treat this sport machine engine to fine fuel for a better burn. The exhaust is funneled through a titanium head pipe and out through the slip-on muffler.

Long A-arms and 20-position adjustable shocks ensure a comfortable and controllable ride.

Long A-arms and 20-position adjustable shocks ensure a comfortable and controllable ride.

Suspension is another item we find impressive on the KFX450R. Front travel on the stocker is 8.5 in. and with the added length in the A-arms this monster should hold to the track on even the harshest off-camber obstacles. Rear suspension is an all-new UNI-TRAK setup. The swinger features stress relieving curved shapes and is a highly rigid torsional casting. This swing-arm and shock combo will give you 10 in. of travel – not bad for a production quad.

Shocks are another great advance in the ever changing world of production ATVs. These stock shocks have a 20-position adjustable compression and rebound feature that should let the beginner get dialed in without getting beaten to death on the track.

Stopping this monster is another area Kawasaki clearly didn’t skimp – Team Green wanted riders to be able to control the power it had built into the machine. Bringing the ride to a stop in a hurry are 163mm front dual piston calipers. In back you’ll find a 200mm petal style setup with a single piston caliper for the peeps that stick the rear in first on the motocross side of life. The battery is located in the front of this machine and is positioned down as far as it will go in the frame to help with the center of gravity for a better handling KFX450R.

Some other notable features are the reinforced rear rims, factory installed Renthal bars and a two-tone seat that has enough grip in the middle for hard acceleration and slick sides for those who hang off the side during cornering.

Kawasaki’s KFX450R can fly through the air with the greatest of ease…and the landings aren’t bad either.

Kawasaki’s KFX450R can fly through the air with the greatest of ease…and the landings aren’t bad either.

Kawasaki has made available a handful of factory accessories for the new KFX450R, but we should make note that for the timid and less experienced the stock form is quite enough. The first of the enhancements is an ECU programmer and signal conversion device. This will allow you to set fuel mapping from your laptop and program it into the computer on the KFX450R. Second is a highly developed silencer, which doesn’t really silence the beast but awakens it for a few more kicks down the straights. Last but not least for all those who like kicking on things the guys over at Kawasaki have made available a kick start and step guard to convert the machine to total performance.

Ride Impressions

Here’s a look at the KFX450R without its clothes.

Here’s a look at the KFX450R without its clothes.

So what does all this mean to the rider? First off, the new Kawasaki has really good power for being stock. The power is similar to other 450cc machines with just factory available power adders. Power is very smooth and controllable throughout the power range.

Handling on the KFX450R is impressive and the rider receives minimal feedback to the bars. This quad reminds me of the Lobo 250r chassis of old. It is light and easy to ride. The suspension is probably the most forgiving in its class, as it is not overly harsh like much of the competition. Jumping the KFX450R is as simple as getting on the throttle and planning the launch. Landing this 394.7-pound racer is comfortable and forgiving.

The brakes are every bit as good as they appear and the stopping power should give any rider confidence when late braking becomes the norm. The quad feels great with the factory fatty renthal bars and the perfect bend – they only needed to be rolled forward a tad to make me feel right at home. Another small but important feature is the ultra easy reverse lever that operates like you would expect one to.

So with the good comes just a touch of maybe not so good. Cutting to the point, the seat was like sitting on a brick and actually felt like it was straight off the a bike. Being a larger rider the pegs felt a bit too high – it felt like I was hovering over the top of the machine…as if the quad was tiny.

The KFX450R is available in Bright White or the more familiar Lime Green.

The KFX450R is available in Bright White or the more familiar Lime Green.


It’s clear Kawasaki has been doing its homework as the KFX450R is indeed a success as a race quad. Most everyone who gets on the new KFX450R will really be happy because it’s equally at home on the track or the trails.

Though it KFX450R hasn’t really changed since being introduced in 2008, it has plenty of potential for the racer at heart.

Comparable Vehicles: Honda TRX450R, Yamaha YFZ450R, Suzuki QuadRacer R450, Polaris Outlaw 450 MXR, Can-Am DS450

2010 Kawasaki KFX450R Specs
Engine:Liquid-cooled, four-stroke, DOHC, four-valve single
Starting system:Electric
Bore x stroke:96 x 62.1mm
Fuel injection system:32-bit digital, with 42mm Keihin throttle body
Ignition:Digital AC-CDI
Transmission:Five-speed with reverse
Final drive:Two-wheel drive, chain
Frame:Aluminum double cradle, racing type
Front suspension / wheel travel:Dual A-arms, coil-over shocks / 8.5 in.
Rear suspension / wheel travel:Swingarm with piggy-back reservoir shock, dual-rate spring / 10.0 in.
Front tires:AT21x7-10
Rear Tires:AT20x10-9
Front brakes:Dual 163mm discs with two-piston calipers
Rear brake:200mm petal-type rotor with single-piston caliper
Length / Width / Height:71.1 in / 46.1 in / 41.9 in
Seat height:30.9 in
Wheelbase:49.4 in
Ground Clearance:4.3 in
Lighting:Dual removable 30w headlights / LED taillight / brake light
Cargo bed capacity:500 lbs, 44.2 W x 32.7 L x 11.1 in. H
Curb weight:394.7 lbs
Fuel capacity:2.6 gal
Footpegs:Sport-style serrated
Colors:Lime Green, Bright White

Related Reading

2008 Kawasaki KFX450R Review

2009 Kawasaki Prairie 360 4×4 Review

2009 Kawasaki Brute Force 650 4x4i Review

Rick Sosebee
Rick Sosebee

Whether he is in Mexico covering the Baja 1000, building ATVs for local racers, or out enjoying the trails, Rick’s passion shows in his stories. Learning to wrench his own machines from his grandfather, Rick also has an undying appreciation for the mechanics of off-road vehicles. Do not let the dirt and mud fool you, though, as Rick also has a deep love for street cars.

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