2015 changes to Yamaha YZ450F & YZ250F

During their debut season the YZ450F and YZ250F have made their mark and shown their potential on both sides of the Atlantic. In the hands of rising star Jeremy Van Horebeek, the YZ450F has raced to 8 consecutive podiums in the MXGP class to give Yamaha 3rd overall in the current World Championship standings.

Over in the USA the YZ250F has had a dominant start in the AMA Nationals, while in Europe the bike has been on the podium in the MX2 World Championship, and currently leads the Women’s Motocross World Championship including two GP race victories. For 2015 these innovative 4-strokes have undergone a number of important changes that are designed to enhance performance and rideability, while a number of stylistic changes give an even sharper image.

Changes have been made to the fuel injection and ignition settings in order to further improve power characteristics, and these revised settings are designed to smooth out the power delivery on the YZ450F, and to give stronger mid-range power on the YZ250F. For easier maintenance the air cleaner cover is equipped with quick release fasteners that replace the bolts on the current bikes. Both models also receive some detail changes to the engine internals.

The 2015 models also benefit from the fitment of new black rims, which – together with the latest graphics – add to the professional ‘factory-bike’

appearance. YRRD (Yamaha Rinaldi R&D) will once again be offering a professional quality race kit for the 2015 YZ250F that features a wide range of performance boosting parts.

The YZ250F kit includes:

 Lightweight forged high compression piston assembly

 ECU with special YRRD mapping and rev limiter raised by 500 rpm

 Modified cylinder head assembly with optimum gas flow

 Intake camshaft assembly with higher lift and revised profile

 Cylinder gasket

 High pressure radiator cap up to maximum 2.0 bar

 Machined crankcase cover for higher rigidity and factory

appearance

 Optional lightweight con rod

Full information at www.yamaha-racingparts.com

YZ450F Technical Upgrades

 Revised FI and ignition settings for smoother delivery

 Revised throttle body components for lighter throttle action

 New quick-release fasteners on the air cleaner cover

 New black wheel rims

 New factory-style graphics

 New lower engine brackets

YZ250F Technical Upgrades

 Revised FI and ignition settings for stronger mid range power

 Revised throttle body components for lighter throttle action

 New quick-release fasteners on the air cleaner cover

 New black wheel rims

 New factory-style graphics

 Modified piston design

 Revised decompression angle on exhaust camshaft for easier

starting

 Special YRRD kit parts available

Availability

YZ250F and YZ450F are available from July onwards.

Technical Specifications

For full technical specifications of all models in the range, please go to:

www.yamaha-motor.co.uk