2011 Yamaha YFZ450R vs. Kawasaki KFX450R 0

In the current era of specialist rides and niche market segments, it’s easy to forget the value of versatility. ATV models span the breadth of race quads to utility mules, but versatility is highly prized in both segments. So while a sport quad might be purpose built for glory on the MX track, it had better be fit for the dunes and burly enough for bar-banging trail escapades. MotoUSA has sourced two such sport quads this past riding season with the 2011 Kawasaki KFX450R and Yamaha YFZ450R SE.

Our original intent wasn’t to compare these sport quads against the other – one being more of a generalized machine and the other a dedicated motocrosser. But, with the 2011 Kawasaki KFX450R located in our Southern California office and the 2011 Yamaha YFZ450R SE at the Oregon headquarters, we realized that they were both being used for the same types of varied riding.

Yamaha does make a general-purpose 450cc sport ATV for 2012, the YFZ450, which is cheaper and closer to the KFX450R in some respects. However, the fact is that riders are purchasing both kinds of machines and trying to shoehorn them into multiple riding disciplines. We don’t stick purely to the moto track and we don’t hide out full-time in the woods. This was a good opportunity to see which one, if any, is more adaptable. It’s likely that regular owners are using them just like we are, so with that in mind, we got the Yamaha and Kawasaki together and hit our favorite riding spots.

All of the riders agreed that the YFZ is still a valuable ride off the track, and the Kawi impresses with its easy, hard-working nature.

All of the riders agreed that the YFZ is still a valuable ride off the track, and the Kawi impresses with its easy, hard-working nature.

2011 Yamaha YFZ450R SE

Yamaha left its popular YFZ450R alone for 2011 but gave the SE model ($8949) a few upgrades centered on aesthetics.

Yamaha left its popular YFZ450R alone for 2011 but gave the SE model ($8949) a few upgrades centered on aesthetics.

Yamaha left its popular YFZ450R alone for 2011 but gave the SE model ($8949) a few upgrades centered on aesthetics. The black/red color scheme and “metallic vertebra” graphics were universally liked by our staff members, and the Yamaha strikes a very aggressive pose with its angular bodywork. Originally we downplayed the quick-release Dzus fasteners that hold the bodywork on, but after living with the YFZ for a year, this feature alone makes the extra price of the SE model well worth it. Maintenance and regular cleaning is much easier with the plastics removed and it only takes a couple minutes to have the SE completely stripped. The swingarm received black treatment which is complemented up front with a black GYTR grab bar and gold drive chain.

The YFZ-R’s mojo is all about motocross. Engineers specifically addressed the needs of track riders when building the R model. The biggest difference between this and the more “all-rounder” Kawasaki are the chassis and suspension. Wheelbase on the Yamaha is only 0.6 inches longer than the Kawi, but the tire width is noticeably wider on the YFZ. This equates to more stability on high-speed sections and through corners. Sliding the YFZ is mindlessly easy, but more importantly, controlling the drift is equally simple.

Part of the reason it’s so manageable is the ergonomic package. All of our testers preferred the open layout on the Yamaha. Seat height is an inch taller than the Kawasaki at 31.9 inches, though you’d swear the KFX perches higher. Sleek bodywork transitions seamlessly into the sculpted seat. Narrow up front and flared in the rear, the seat’s shape helps the rider move freely and also to hang off the rear of the ATV. Seat foam is very comfortable as well. Though skinny, the Yamaha seat is very comfortable by sport-quad standards.

“This thing is a race quad,” says expert-level ATV rider Scot Gibson. “The ergos are phenomenal on this thing. You can move around, you can get forward and back.”

Footpegs are a burly 2.6-inches wide with large kick-up on the ends to allow excellent grip. Neither machine comes with nerf bars or foot nets. Handlebars are four-position adjustable which adds to the versatility. The clamps are reversible and there are two sets of mounting holes. Our ProTapers were slightly tweaked in a crash so we took the opportunity to try out a set of Fasst Co. Flexx handlebars to help take the sting out of any jarring impacts. The bars do help, but the Yamaha scores high with our testers for its Kayaba shocks regardless. The front shocks are 44mm KYB units with Kashima coating and full adjustability (rebound, high/low-speed compression and rebound). Combined with long dual A-arms, the shocks allow wheel travel up to 9.8 inches before bottoming. The shock springs are red and the piggyback reservoir black to match the SE aesthetics.

Sleek bodywork transitions seamlessly into the sculpted seat. Narrow up front and flared in the rear, the seat’s shape helps the rider move freely and also to hang off the rear of the ATV.

Sleek bodywork transitions seamlessly into the sculpted seat. Narrow up front and flared in the rear, the seat’s shape helps the rider move freely and also to hang off the rear of the ATV.

Out back is a cast aluminum swingarm mated to straight axles and a 46mm KYB piggyback shock. This arrangement allows a full 11 inches of travel from the 20-inch rear tires.

“This thing will gobble up anything,” says Gibson. “It’s made for the motocross track but we put it through its test off-road and I absolutely loved it in the woods environment.”

Dunlop KT356 rear tires and Dunlop KT351 front tirescontribute to a wider stance than the Kawasaki. In the dunes there’s no doubt that the Yamaha is superior with more stability and much improved cornering as a result. Jumping is more secure and the higher-spec suspension is better able to absorb heavy landings and small, choppy sand as well. The dunes also allow the open space needed to use the YFZ’s top-end scream and tall gearing. Read more about the sand performance in our 2011 Yamaha YFZ450R SE ATV Dune Review.

Keeping it pinned and rowing through the five-speed gearbox, the YFZ delivers all 449cc of power. The liquid-cooled engine uses dual overhead cams to control five titanium valves. Yamaha says the engine is tuned to maximize midrange torque, but we all consider it best with more revs. With a counterbalance, the SE spins up through the rpm range quickly and with minimal vibrations, but wringing it out does deliver some buzzing through the handlebars. A 42mm Mikuni throttle body dishes out fuel through a 12-hole injector while the compression ratio is 11.6:1 inside the 95 x 63.4mm bore and stroke cylinder.

“It’s got a really revvy motor that doesn’t quite have the bottom end and midrange of the Kawasaki, but a little clutch action and a lot of throttle takes care of that,” Gibson notes.

Jumping is more secure and the higher-spec suspension is better able to absorb heavy landings and small, choppy sand as well.

Jumping is more secure and the higher-spec suspension is better able to absorb heavy landings and small, choppy sand as well.

Starting on both ATVs is easy with consistent fuel injection, though the Yamaha has a better battery. Dead power supplies plagued our testing throughout but the YFZ holds its juice better than the Kawi. Cold weather is tough on the relatively small-capacity batteries. Fortunately, getting to the electrical supply is easy, and working on the Yamaha is a joy. The aluminum frame is bolted together and the oil tank is integrated into the engine crankcase. Plus, getting into the serious components is made easier with the SE version’s quick-access Dzus fasteners on the bodywork. Not only is the easy access appreciated for general cleaning, but racers will find it useful for making repairs/changes between motos.

“Far and away this is the better looking bike,” says Hutchison, getting back to the good stuff. “It’s trick. All the blacked-out components… It’s sinister in the way it looks and I dig it… Until you have dismantled an ATV using the Dzus fasteners versus Alan screws, a Phillips-head screwdriver, or whatever it is, you’re not going to understand how awesome it is.”

Our riders’ biggest complaints was the lack of a reverse gear, which we won’t fault Yamaha for. It doesn’t pretend that the YFZ450R is anything other than a motocross quad and offers other models for non-moto use. Our testers all recognize this, but each would still willingly sacrifice additional weight on a racetrack for the ability to get out of a jam when riding off-road. Even the trail-oriented YFZ450 doesn’t have reverse, so Yamaha sport riders who want to go backward without getting off and pulling will have to move into the Raptor family.

2011 YZF450R SE Technical Specs:

Engine: 449cc, DOHC, 5-valve
Chassis: Bolted aluminum
Transmission: 5-speed manual
Weight (dry): 405 pounds (claimed)
MSRP: $8949

2011 Kawasaki KFX450R

Kawasaki has left its KFX450R well enough alone but it continues to hold the favor of many sport ATV riders for one important reason – reverse.

Kawasaki has left its KFX450R well enough alone but it continues to hold the favor of many sport ATV riders for one important reason – reverse.

Kawasaki has left its KFX450R well enough alone but it continues to hold the favor of many sport ATV riders for one important reason – reverse. There are certainly other features and characteristics about the KFX that make it different from other sport quads, but the 450 class is increasingly devoid of four-wheelers that back up. It’s definitely one of our favorite attributes, but there’s much more to this green meanie.

“The big bonus on this for me is that it has reverse,” says Gibson. “Any quad in the woods definitely needs the ability to back up.”

Kawasaki uses a 449cc engine with DOHC but only four titanium valves compared to Yamaha’s five. Bore and stroke are similar at 96mm x 62.1mm. The Kawi employs a 42mm Keihin throttle body for its digital fuel injection (DFI) system. One tester noted that the YFZ fuels a little cleaner, but the KFX runs great and comes to life easily with its electric start. Neither quad offers a backup kick start, and the KFX eats batteries with a vengeance.

The torquey engine uses strong bottom-end and midrange punch to keep the Kawasaki feeling lively on the trails.

The torquey engine uses strong bottom-end and midrange punch to keep the Kawasaki feeling lively on the trails.

The five-speed transmission places reverse below first gear, so the rider actuates with a reverse-lock release lever and then taps down into reverse. As for the rest of the transmission, the gears are relatively close together which makes upshifting a seamless affair, even when poorly timed. But, in order to hang with the YFZ it almost needs a sixth gear, or rather wider spacing between the existing five cogs. First is very low and most tight trail riding can be done in second. Spacing them out, or simply adjusting the final drive ratio would give the KFX a bit longer legs. As it is, the Kawi shifts well and is well suited to the engine character. The 450R puts power down to the ground with authority from off-idle all the way through a robust midrange. Once the revs get into the upper limits, the Kawasaki stops accelerating and falls off quickly. Short-shifting works best and the green ATV as an easy clutch pull. It makes for easy launches and works well for less experienced riders.

“All around this bike is money,” adds Hutch. “It’s got reverse, it’s got the best bottom end, the best midrange, it’s a narrow width and it has kind of a stubby wheelbase. When you’re out in the woods, this thing is super-agile.”

That agility also won over our other testers. In the dunes and on fast sections it equates to a tendency to oversteer, but switchbacks and situations that require instant corrections favor the green quad. Where the narrower track is more difficult to span ruts, it’s better at holding a high line around them, and can squeeze past obstacles. Narrower front tires help turn the Kawi quicker but the Yamaha’s front treads have a traction advantage in the dunes as it slides more uniformly front-to-rear. Our riders commented on a shorter wheelbase, but it’s only 0.6 inches shorter at 49.4 inches. The punchy, tractable engine and lighter weight (392 lbs. claimed wet) helps give the sensation of closer-set wheels.

Where the Yamaha gets praised for its roomy layout, the Kawasaki is a much tighter seating arrangement. Most of our testers wished for more space and noted that the fenders create stopping points for moving around the cockpit. However, compact ergonomics are only a bummer if you’re a tall rider. The Renthal Fatbar handlebars are closer to the rider’s lap and create more of a hunched position when standing. Also, the footpegs aren’t quite as stout as the Yamaha’s

“I’m a short guy. When I get in here, everything is right there,” says Ken in reference to the controls.

“It’s a little less-aggressive riding position,” adds the slightly taller Gibson. “The riding compartment is a little cramped. Nothing that is uncomfortable.”

The aluminum chassis is designed to be very stiff and makes use of a similar single-tube lower design as the Yamaha which allows for longer lower A-arms. The rear piggyback Kayaba shock is adjustable with high/low compression and rebound. Our testers were happy with the performance of the rear end with its aluminum swingarm and 10 inches of travel, but weren’t quite as pleased with the front end, its 8.5 inches of travel and dual-rate springs.

“The faster you go, the more the suspension rattles you. It’s constantly shaking,” says Hutchison regarding the front end.

The shorter overall suspension travel isn’t the issue so much as the rigidity of the Kayaba shocks. Both front components are piggyback units with high/low compression, rebound and preload adjustment. In order to absorb the larger impacts blowing through the stroke and bottoming, we have to run the shocks fairly stiff, and the compliance on small trail garbage is not comfortable. Bumps are transferred to the rider and it takes a lot of effort to control the handlebars.

Most of our testers wished for more space and noted that the fenders create stopping points for moving around the cockpit.

Most of our testers wished for more space and noted that the fenders create stopping points for moving around the cockpit.

Even though the Kawasaki isn’t a special edition version it still has some nice features, plus a lower MSRP ($8099), like the Renthal bars, LED brake lights, heel cups, skidplates and lapped front and rear fenders. The fender design allows for individual replacement when damaged or for a smaller profile during sand riding. Kawasaki also equips the KFX450R with an easy-to-use parking brake.

“Imitation is the sincerest form of flattery,” muses Hutchison. “Finally they’ve got the Yamaha-style parking brake which just makes this thing even better.”

Our riders also liked the Kawasaki’s headlights better, not necessarily because they shine brighter, but because they proved more durable and are tucked away more effectively to shield from abuse. Our Yamaha had a light housing broken simply from vibration, which was a bummer. They’re also physically larger than the KFX’s which exposes them to roost and debris. The Kawi has workable lights that are relatively well protected.

As it turns out, the Kawi’s strengths are its usable engine with reverse and agile handling, while cramped ergos and rough suspension hold it back. The Yamaha is opposite with amazing rider comfort and stellar suspension, but a high-rpm engine that only goes forward. Either of these sport ATVs can be the right choice depending on where you ride.

With a big push in recent years for motocross-specific quads, there has been a slight loss for hard-core 450 riders who need or want to take their machines away from the track. Our Southern Oregon area is a perfect example. The two public motocross tracks within an hour drive both shut down during the winter due to mud and snow, and you can bet damn well that our ATV population isn’t just packing it in with a shrug of the shoulders. With a slight bias toward our tight trails, we were very pleased to find that the MX-model Yamaha is still plenty capable of heading away from groomed jumps. The most aggressive of our testers preferred the Yamaha overall, but the other two riders would happily adopt either into their personal garages. All of the riders agreed that the YFZ is still a valuable ride off the track, and the Kawi impresses with its easy-going, hard-working nature.

2011 Kawasaki KFX450R Specs:

Engine: 449cc, DOHC, 4-valve
Chassis: Aluminum
Transmission: 5-speed manual, reverse
Weight (dry): 392 (claimed)
MSRP: $8099
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