2010 Yamaha YZ450F Introduction

The 2010 Yamaha YZ450F has taken on a nearly mythical status over the past year, as Yamaha poked fun at with their rumors video last week. Well, the bike is real, and it has arrived. We'll be riding and reviewing the bike in the future, but for now, here's what Yamaha has to say about it.

Click here to open the PDF file with full mechanical specs.

The first thing you notice about the new engine is that the exhaust pipe is missing. With the cylinder head reversed so the intake comes in the front and the exhaust out the rear, the exhaust pipe now features a “Tornado” coiled design that moved it to where the airbox used to be. The intake is located at the very front of the engine allowing for the most direct path straight into the 44mm Keihen Fuel Injection throttle body. Helping create that direct path is the rearward slanted layout of the cylinder and cylinder head.

Once you get past the visible changes on the outside of the engine the inside is just as different. The new engine features a four-titanium valve head with a pent-roof combustion chamber shape. This layout was found to work the best with the new fuel injection system. The piston itself is offset on the crank to eliminate power robbing friction that is caused by piston rubbing on the cylinder wall during combustion.

The YZ450F features a powerful titanium 4-valve DOHC liquid cooled single cylinder 449cc engine, using a battery-less electronic fuel injection system.  Crack the throttle and instantly feel the rear wheel churning up dirt. That kind of instant throttle response is at the heart of the new engine. Power is there whenever you need it at a moments notice. All new intake and exhaust cams, along with a higher compression piston have the 2010 YZ450F battling for holeshot after holeshot.

The technologically advanced 2010 YZ450Fis equipped with a tunable electronic fuel injection system featuring a 44 mm Keihen® throttle body, and 12-hole injector which provides exceptional atomization of the fuel for maximum power, unrivaled throttle response and automatic altitude and temperature adjustment.  The system also includes idle speed control for easy, reliable startup.  Through the use of the GYTR Power Tuner you are able to tune the ignition and fuel injection system to better suit your individual needs with a simple standalone device that doesn’t require a laptop, battery or a PhD to operate.  

The new YZ450F features a lightweight, Bilateral Beam Frame with over 16 different pieces made up of Extruded, Forged and Die-Cast Aluminum. Developed with the goal of being the ultimate cornering motocross bike the unique double S-bend shape of the frame plays a key role in the positioning of the new engine layout as well as the overall nimble handling feel of the bike. Hitting inside lines, carving through deep ruts and making quick direction changes are no problem for the 2010 YZ450F new chassis.

Yamaha prides itself on great out of the crate suspension and the 2010 YZ450F features the same KYB SS Forks that have garnered much of that acclaim. To work with the new chassis the forks have been lengthened 10mm and re-valved with a new dampening character.

The KYB Shock features a new Piggyback design thanks to the additional room that the new engine layout allows. The shock is now centrally mounted in both the bilateral beam frame and swingarm, which allow for the shock to better absorb the rigors motocross throws at it.

The all-new YZ450F has the benefit of years of Yamaha Factory Racing experience – one resulting highlight is simple race prep and service.  Common bolts and nuts are used from most engine and plastic parts.  The oil tank is integrated with the crankcase so servicing the engine is a snap.

The YZ450F also boasts ProTaper® handlebars with four-position adjustability, allowing riders of any size to find a comfortable setting.  The seat design is very flat, allowing plenty of freedom for the rider to be able to slide back and forth to get in the right body position on the bike.

The new YZ450F comes in a standard color Team Yamaha Blue/White or in a second color White/Red.