2004 Official factory service manual for Yamaha YFZ450S ATV Quad., Page 119Get this manual
ADJUSTING THE REAR SHOCK ABSORBER
Steering nut wrench PNYU-33975, 90890-01443 Locknut 45 Nm (4.5 kg, 32 ft lb)
NOTE: Always tighten the locknut against the adjusting ring, then torque it to specificationLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL
5Install: air filter case with air intake duct