Yamaha’s 2004 YFZ450

Attention ATV racers and hard-core sport riders, it’s time to get excited! Yamaha’s newest entry into the sport performance market will knock your socks off! Year after year OEMs go the extra mile in the name of releasing the latest-greatest-hi-tech and fastest dirt bike for their dealer showrooms. None of the big four have really bothered to release a serious race worthy ATV, so die hard ATV racers have reached deep into their bank accounts and shelled out upwards of $25,000 to build race worthy dirt-bike based machines from the ground up themselves. Those days are over! Yamaha’s new YFZ450 is made especially for racing. It is the 250R replacement that ATV racers world wide have been waiting for, only Yamaha made it ten times better than the R! After seeing the photos and reading what this ATV is all about, we’re sure you’ll agree, – this changes everything!

Before we give you the low down on this incredible machine. With translator by our side, we spoke with the chief designer of the YFZ, who wished not to be identified. “The YFZ is four years in the making. We’re very proud of our constant communication with Yamaha America. The YFZ is our greatest accomplishment ever” Mind you, this man was the creator of the YZ426, the ground breaking four-stroke power-plant changed the way people think of four-stroke power. That says a lot about their commitment to this machine. What’s more, he ignored his vacation time and was on hand to announce Yamaha’s ground-breaking ATV. A very proud man and diservingly so as you’ll see.

All quotes are directly from Yamaha engineers and technicians…

Front Suspension
Race ready suspension from the dealer showroom? Yes it’s true!Most stock systems will not work for an aggressive racing application. Yamaha wanted only the best for their new YFZ. “We wanted to outfit it with suspension that worked just as well as any aftermarket suspension on the market, so we tested with every shock maker in the business”. The end result? Yamaha went with the lightest unsprung mass units possible in order to allow the wheel to react quicker and easier. Their choice, — nitrogen filled remote reservoir piggy back Kayaba shocks. The shocks offer adjustable preload, dampening, rebound and compression for different tracks.

In order to reduce unsprung weight the YFZ comes stock with aluminum upper A-arms and forged aluminum steering knuckles. The lower A-arms are steel and have a reduction in the lower portion of the arms which allow the YFZ to boast 9.1″ of wheel travel. Easy maintenance is allowed with zerk fittings all the way around.

Rear Suspension
Here the aluminum cast sub frame and swingarm can be seen. The high tensile strength smaller diameter steel used on the frame is lighter than typical OEM ATV frames.Yamaha simply said they wanted the best suspension available and continued right where they left off up front. The rear suspension seems just as capable. “We took the three pivot points in the rear suspension and copied the cutting edge YZ dirt bike technology. This puts the shock and the rear brake very far forward- it centralizes all that mass so it suspends the ATV perfectly”. Wheel travel is 10.1″. The rear linkage is YZ450F type and made from forged aluminum. The rear swing arm is cast aluminum and incredibly light weight. It’s anti-squat design allows the ATV to accelerate forward rather than wheelying out of a turn.

Strangely enough, Yamaha elected to use a different brand of shock on the rear. “We spent a lot a time with suspension. We didn’t want to compromise. We only cared for what worked the best for this ATV.” With that said, the top-of-the-line piggyback nitrogen-filled completely-adjustable Showa shock got the nod.

Brakes
The front brakes are duel calipers, while the rear only have one caliper. “We wanted the light-touch-feel of the YZ bike brakes and we succeeded, it’s got excellent stopping power just like the YZ.

Tires
The front Dunlop tires look similar to the Raptor front tires but they have a thicker sidewall, which doesn’t allow the tire to roll from side to side. The rears are all new Dunlop radials. They were developed specifically for the new YFZ450. “These tires will probably be the best tires you can race with on a track. There is a lot of critical areas with tire development. We spent a lot of time here. The tire needs to be able to slide well into a turn, keep traction through the turn and accelerate out. We think a lot of riders will be using these tires on other ATVs, they’re that good.” Tires are mounted on light weight aluminum wheels all around.

Controls and ergonomics
Yamaha went the extra mile on many parts. The racing clutch perch is one example. It comes complete with an on-the-fly adjusting knob. The adjustment is easily exposed after removing the lever operated parking brake mechanism. The seat is low and flat and allows plenty of movement for aggressive riding. Front brake and clutch levers are right off the YZ. Both are adjustable for different size hands. Even the little details were made specifically for racing. By law, Yamaha had to equip the ATV with a parking brake. Yamaha very cleverly made it easy for a racer to discard the parking brake system. Once it is removed the rider can get at the quick-adjust clutch mechanism. There is no need to buy another clutch perch or front brake lever mechanism.

The YFZ comes with a 45mm wide foot peg with a tilt at the end for extra support while cornering. The front fenders are pushed forward to stop the rider from rubbing his knees on the front fenders. It’s obvious that their focus was to allow the racer to take the ATV directly from the showroom to the race track. Well thought out details are abundant!

Carburetor and Air intake
Take off the seat and the battery and airbox are visible. A 20% increase in power can be gained when removing the airbox lid, changing the main jet and slipping on a tail pipe.According to Yamaha, at this time, fuel injected mapping is very difficult to work correctly in order to get the most out of the YFZ’s potent four-stroke motor, so Yamaha uses the best carburetor available for a four-stroke engine, the race-inspired Keihin 39mm FCR carburetor with throttle position sensor at the push of a button.

Air intake is provided with a state-of-the-art large volume, one-piece boot and boasts a no-tools removal system.

 

 

Motor
This is not a modern-day highly advanced, high-powered four-stroke motorcycle engine – it’s a modern-day highly-advanced, high-powered four-stroke ATV engine!Perhaps the most exciting news comes from the the YFZ’s power-plant. Yamaha didn’t tame down their world-leading four-stroke technology one bit. Instead they went all out and delivered a power-plant that all ATV racing enthusiast can be proud of. Yamaha watched the National ATV racing scene closely and made sure the YFZ passed all the AMA/ATVA standards for closed course competition. Yamaha skipped the reverse gear, shelved all unnecessary parts and went full-on race!

The 439cc liquid-cooled DOHC engine is very similar to the YZ450F engine, which means it rips to say the least! It snaps to life via electric start, but the motor has all the hardware ready for a bolt on YZ450F kick starter, and the YFZ’s carb awaits Yamaha’s hot-start button. This means serious racers will toss the battery and all the electric starting hardware, shed over twenty pounds of dead weight and start their race quad with a kick. Yamaha’s kick starter accessory even includes a template for cutting the perfect amount of material off the rear fender to allow your foot to pass by the fenders. Very considerate of them, wouldn’t you say?

The stroke was decreased to allow a 439cc displacement. The YZ450F crank will fit right into the motor for those wanting the maximum 450cc size. Yamaha tells us most will be extremely happy with the current set up however.

This cutaway exposes the ratchet-type five-speed tranny The gears are made wider than the YZ450F bike to withstand the extra strain an ATV puts on the motor.

This cutaway shows the titanium five valve head. The short skirt piston allows the potent thumper to rev to the moon!Many of the parts are directly taken fromthe YZ450F. No corners are cut for ATV racers. Those days are over! Five titanium valves, an all aluminum body – ceramic coated cylinder, ratchet type five-speed shifter, direct ignition coil, and magnesium valve cover all shared from the wicked fast YZ450F. The intake camshaft is the same as the YZ450F, while the exhaust cam shaft, with its easy start auto decompression cam pin and lever, is the same one found on Yamaha’s WR450F.

The forged piston is based on the YZ450F, but is newly designed especially for the YFZ quad. Piston pin diameter is increased from the YZ450F, but a minimal piston skirt is used to allow the YFZ to rev to the moon! The compression ratio is 11.9:1 so you’ll want to feed this monster at least premium unleaded fuel.

Yamaha’s direct ignition coil is a first for an ATV. The ignition coil is integrated into the spark plug cap and timing control is provided by Yamaha’s 3D map. The YFZ’s race-proven clutch is based on the YZ450F but uses thicker plates for increase heat capacity. Thankfully, Yamaha uses the same magnesium quick-access clutch cover as the YZ450F.

Yamaha’s comment on the motor, “We really feel that this is the ATV that everyone has been waiting for. We couldn’t keep up with this motor during testing, so we hired four professional motocross bike racers. They were doing all the jumps they did on their bikes. Its power-band is right there with today’s high tech motorcycle engine. It’s definitely the quickest ATV available”.

Genuine Yamaha Accessories
Yamaha is serious about their Genuine Yamaha Technology Accessories.If waiting for aftermarket parts to be built isn’t your game, Yamaha offers some pretty impressive bolt on accessories built especially for improved performance and racing applications. Again, Yamaha’s focus was to offer a race winning ATV directly from the dealer showroom. Since there are several different types of ATV racing, different components are available right from the dealer, including performance kits (in different stages), which include slip on pipes, full exhaust systems, pistons, jetting etc. – all made to reduce weight and increase race track performance. A-arm and axles are available to widen the machine for motocross and TT specific racing. A billet aluminum clutch basket, pressure plate, clutch kit and digital ignition module are available. Billet aluminum kick starters, shifters and rear brake pedals are also available. As are nerf bars, skid plates, push bars and rear grab bars.

Cut to the chase, will it lead the race?
Barry Hawk (7-time GNCC champ) pitches the YFZ sideways. Barry says he’s never ridden a faster and better handling ATV! By the way, when was the last time you saw a manufacture market their ATV with racing numbers on it?If you’ve read the above, you have to agree – it’s obvious that Yamaha has done their homework and delivered what die hard ATV racers have been asking for. They report that their new YFZ450 is the quickest accelerating, lightest and best handling machine available. The YFZ uses all the true cutting edge technology available today, including, aluminum, titanium and magnesium components. We remind you, it’s specifically made for racing! 7-time GNCC ATV champion, Barry Hawk rode the YFZ and claims it’s the best handling and fastest ATV he’s ever ridden! Pretty impressive words from a pretty impressive ATV racer. The YFZ’s print advertising even features Hawk’s number six on the plastic, — a first in ATV marketing.

Its dry weight of 350lbs. is 22 pounds lighter than Suzuki’s new Z400 and 65 pounds lighter than the Polaris Predator. When the electric start hardware is removed an additional twenty pounds are subtracted making it even lighter than the now defunct Cannondale.

Yamaha has specifically made everything with major attention to race track performance. Every part has been tweaked with race bred performance in mind from the controls to the five valve titanium cylinder head. Yamaha led the way with its 1998 YZ426 motorcycle motor and proved four-stroke power can hit just as hard as two-strokes can. Now the sportiest of all sport quads comes out of the crate with this borrowed YZ technology. Everything from the brake and clutch levers to a flat low seat for optimized sport riding has been incorporated. The cam shaft, cylinder body, valves, cam chain tensioner, even the magnesium crankcase cover all come straight from the race winning YZ drawing board.

“We’re all really excited about this ATV. It’s ten times better than anything that has ever been released. We feel that it is going to help spur the racing market out by allowing the buyer to go racing right from the showroom”. When asked if Yamaha was considering a race team or contingency support program the following answer was given, “All of our effort was spent on providing the vehicle at the best possible price so that more people could become involved and experience racing. Rather than promote something that we don’t build, we decided to build the best ATV that everyone will surely want to race. We’re a manufacture, we wanted to focus on manufacturing and keep the price tag of the machine as low as possible.”

For finally releasing what the ATV racing industry has been asking for for so many years, we salute Yamaha for having the guts to go through with it. But we aren’t surprised of Yamaha’s new instrumental sport quad. After all it was Yamaha who kept the sport performance segment going by continually keeping their high-performance Banshee in production, while other OEMs quickly turned away from the sport segment when countless lawyers jumped on the bandwagon and attacked with frivolous lawsuits aimed at the big four. No sport can survive without the addition of new competitors – Yamaha continually provided the vehicle to those new enthusiasts. Although they didn’t’t invent the sport quad, Yamaha rightly deserves credit for helping to keep the sport segment alive. Today the sport is thriving and the Banshee is still a part of their line up. Yamaha is the only manufacture to continue selling two-stroke ATVs. What’s more is the all-time leading sport ATV is the Yamaha Warrior.And with their Raptor 660R, Yamaha proves they aren’t afraid to think outside the box. So without a doubt, we’re not surprised that Yamaha leads the way with what we will call the ATV that changes everything.

And the best part for last. The manufacturers suggested retail price of the 2004 Yamaha YZF450 is $6,899, an incredible value, we’re sure you’ll agree.
The new YFZ and their GYT-R accessories for it are available at Yamaha dealers nationwide right now!

 

Engine
Type:	439cc 4-Stroke Single, Liquid-Cooled w/Fan, Titanium 5-Valve DOHC
Bore x Stroke:	95mm x 62mm
Compression Ratio:	11.9:1
Carburetion:	Keihin 39mm FCR w/Throttle Position Sensor
Ignition:	DC-CDI w/3D Mapping
Starting System:	Electric
Transmission:	5-Speed Manual Clutch
Drive Train:	2WD; Sealed O-Ring Chain
Chassis
Suspension/Front:	Independent Double Wishbone, 9.1” of Travel w/Rebound, Compression and Threaded Preload Adjustment
Suspension/Rear:	Cast Aluminum Swingarm, 10.1” of Travel w/Rebound, Compression and Threaded Preload Adjustment
Brakes/Front:	Dual, Twin Piston Hydraulic Discs
Brakes/Rear:	Hydraulic Disc
Tires/Front:	AT21x7-10 Radial
Tires/Rear:	AT20x10-9 Radial
Dimensions:	L x W x H 72.4” x 46.1” x 42.9”
Seat Height:	31.5”
Wheelbase:	50.4”
Ground Clearance:	4.4”
Fuel Capacity:	2.6 Gallons
Dry Weight:	350 Lbs.
Other
Lighting:	Dual 30W Krypton Multi-Reflector Headlights & 21/5W Brake Light
Colors:	Team Yamaha Blue, White/Red
Warranty:	6 Month (Limited Factory Warranty)

 

Check back with ATV Scene.com in about a week. We’re setting ATV Scene.com’s Kory Ellis loose on the new Yamaha YFZ450!

Tags:

Comments

comments