The boys in blue paid us a visit a few weeks ago to show us what's in store for the 2008 Yamahas, and now that the embargo restriction has finally expired we can share that info with you as well. Here's a quick run down of some of the changes according to Yamaha, as well as a few photos.
ALL BIKES:
Shared improvements on the 2008 YZ125, YZ250, YZ250F, and YZ450F
- - Weight reduction on fork axle bracket
- All new front brake system (from the '07 YZ250F)
- New front fork guards
- Shorter front fork tube
2008 YZ125
- - Redesigned reed block for increased midrange power and improved throttle response
- Stiffer fork springs for a more balanced suspension feel
- Front and rear wave rotors (YZ125 and YZ250)
Both the YZ125 and YZF250 features wave rotors front and rear for 2008
The '08 YZ250F shift lever has been lowered 5mm, bringing it level with the footpeg.
2008 YZ250F
Yamaha's goal for the 2008 YZ250F was more horsepower and improved handling, which they feel they have accomplished with the following changes:
- - An all-new Bridgestone tire
- Increased compression ratio for more power, less friction, and small weight savings
- Needle changed from single taper to double for more precisely metered fuel output
- Brake pedal moved in 14mm to make it less susceptible to damage
- Shift lever lowered 5mm to make it level with the footpeg
2008 YZ450F
For the 2008 YZ450F, Yamaha tells us they have improved the power delivery, redesigned the exhaust system and frame, improved cornering and made several other incremental changes. But at first glance the most noticeable change to the '08 edition of the YZ450F is the new shorty muffler:
- - Increased low to midrange horsepower
- Exhaust intake track straightened to reduce turbulence and increase airflow for improved low to mid throttle response
- Piston clearances tightened for reduced engine noise
- Switched from plastic to aluminum crankcase plugs
- All new headpipe to match new muffler for better low to midrange performance
- Steering head shortened 5mm and frame shaved down for improved handling and cornering
- Bar mounts raised 4mm
- Front tire changed to Dunlop D742FA and rear to a 120/80-19 Dunlop D756 for increased traction in corners
- Cam timing changed for better throttle response, increased controllability and improved low to midrange power
- All new shorty muffler is six inches shorter than in 2007, shaving over a half pound of weight and creating more forward mass for improved handling
The most noticable visiblle change on the '08 YZ450F is it's all new shorty muffler.
2008 YZ FOUR-STROKE SHARED CHANGES
Both the 250F and 450F share the following changes for 2008:
- - Footpeg widened 10mm and lowered 5mm for increased rider area
- Enlarged compression valve port in the forks for a better dampening character and more plush feel
- Stiffer front fork springs on both the YZ250F and YZ450F, and a stiffer shock spring on the YZ250F for improved suspension performance
- Tightened tolerances between gears to reduce engine noise
- Redesigned lower triple clamp
- Black ignition, clutch and oil filter covers
Well there you have it; that is a quick rundown of the changes to the YZs for 2008. As soon as we get a chance to put the bikes through their paces we'll bring you our official first impressions here at twmx.com, and of course our annual shootouts later in the year in TransWorld Motocross magazine
Colei tudo daqui:
http://www.transworldmotocross.com/mx/p ... 25,00.html
E ai, quem pode traduzir isso para gente? Por se tratar de dados tecnicos, tradutores (softwares) nao funcionan!
abraço
