Not everyone can afford a new bike so fixing up old reliable one can be a good option. For this build we took our bike to Race Tech, who is now modifying and building engines. Race Tech rebuilt the engine with the full Wrench Rabbit kit. This kit has all of the bearings for the entire engine, a new crankshaft, complete gaskets, piston kit and cam chain—that’s a lot in one box.
The 2008 YZ450F was a top-notch bike back then with some great characteristics. There are some great traits on the old bike and if you feel good on your old steed then maybe you should consider a rebuild rather than a new bike. We went a little overboard with our rebuild and added some bling, but when you have a nine-year-old bike your wheels and plastic will need some attention.
Race Tech also went through our old shock and forks, and they performed like new. Check out the test with Bruce Marada to get his thoughts.
Just about every part listed below can be purchased RockyMountainATVMC.com—as well as all OEM parts.
Race Tech Engine Services focused on improving the performance of the 2008 YZ450F engine without sacrificing reliability.
Hi-Performance Full Port – Full porting increases flow and velocity for max efficiency (ensured using flow bench data). Includes modifying the combustion chamber.
Hi-Performance Five-Angle Valve Job – A Hi-Performance Five-Angle-Radius Valve Job from Race Tech adds horsepower without sacrificing reliability by creating the best flow possible at the valve seat. Adding additional angles and a radius to the valve ports increases air speed and flow. Valve to seat concentricity of less than .001". Includes spec sheet.
Cylinder Honing – Race Tech uses a Sunnen Precision Hone to provide a diamond hone finish using specialty stones for nikasil (the special stones are critical). An essential process every time a piston ring is replaced. This is true for all cylinder materials but especially true for chrome and nikasil bores. Provides a fresh surface inside on cylinder wall. This is critical yet often overlooked or misunderstood component for producing reliable, repeatable horsepower.
For the suspension Race Tech replaced wear parts, re-sprung, and revalved the suspension.
On the forks we went with a .48kg spring rate for a 190 pound intermediate motocrosser combined with Race Tech's Fork Gold Valve Kit to personalize the suspension setup to provide a plush but firm front end feel with great bottoming resistance.
On the shock we went with a 5.6kg spring rate and Race Tech's G3-LD Shock Gold Valve Kit. The LD stands for Low Deflection to absorb versus deflecting off bumps. The personalized valving setup provides a plush feel and improves traction while drastically improving bottoming resistance.
Hot Rods complete bottom end kit includes complete crankshaft, main bearing seal kit, transmission bearings, output shaft, water pump rebuild kit, cam chain from Hot Cams and complete engine gasket kit. Also includes Vertex Pistons pro replica piston kit (ring, pin and clips).
Two-Stage air filter.
Hinson Clutch Components
Fibers, steels and springs clutch kit.
Powerbomb SS header
Steering stem bearing kit.
Linkage rebuild kit.
Swing arm kit.
Front and rear sprocket.
604 fat bars.
Front and rear brake pads.
MX 3S front 80/100-21.
MX 3S rear 120/80-19.
Semi-Custom graphics kit.
Pre printed number plates backgrounds.
Custom cool seat cover.
Elite clutch perch.
Front brake lever.
Hour meter and mount.
Rear brake pedal.
Complete wheel set.
Oversized front rotor.
Brake bolt kit.
Sprocket bolt kit.
Full plastic kit.
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