The 1998-2008 Yamaha YZ, Yamaha WR 4-Stroke off-road and motocross bike repair manual by Haynes, covers the following models:
Book Excerpt: 1998-2008 Yamaha YZ & WR 4-Stroke Motocross & Off-Road Bikes Repair Manual
- Yamaha YZ250F, 2001-2008
- Yamaha YZ400F, 1998-1999
- Yamaha YZ426F, 2000-2002
- Yamaha YZ450F, 2003-2008
- Yamaha WR250F, 2001-2008
- Yamaha WR400F, 1998-2000
- Yamaha WR426F, 2001-2002
- Yamaha WR450F, 2003-2008
TIRES/WHEELS: GENERAL CHECK
Routine tire and wheel check should be made with the realization that your safety depends to a great extent on their condition.
BRAKE PEDAL REMOVAL AND INSTALLATION
Check the tires carefully for cuts, tears embedded nails or other sharp objects and excessive wear.
Operation of the motorcycle with excessively worn tires is extremely hazardous, as traction and handling are directly affected.
Check the tread depth at the center of the tire and compare it to the value listed in this Chapter?s specifications.
Yamaha doesn't specify a minimum tread depth for some models, but as a general rule, tires should be replaced with a new ones when the tread knobs are worn to 8 mm (5/16 inch) or less for safety's sake, but performance, you?ll want to replace a tire long before it gets that worn.
Repair or replace punctured tires as soon as damage is noted. Do not try to patch a torn tire, as wheel balance and tire reliability may be impaired.
Check the tire pressures when the tires are cold and keep them properly inflated (refer to Daily checks at the front of this manual).
Proper air pressure will increase tire life and provide maximum stability and ride comfort.
Keep in mind that low tire pressure may cause the tire to slip on the rim and come off, while high tire pressure will cause abnormal tread wear and unsafe handling.
The wheels should be kept clean and checked periodically for cracks, bending, loose spokes and rust. Never attempt to repair damaged wheels; they must be replaced with new ones. Loose spokes can be tightened with a spoke wrench (see illustration), but be careful not to overtighten and distort the wheel rim.
Check the valve stem locknuts to make sure they are tight. Also, make sure the valve stem cap is in place and tight. If it missing install a new one made of metal or harden plastic.
Check the tightness of the locknut on the rim lock (see illustration). If it?s loose, tighten it securely.
- Support the bike securely upright so it can?t be knocked over during this procedure.
- Unhook the pedal return spring from the frame (see illustration).
- Remove the cotter pin and clevis pin to detach the master cylinder pushrod from the pedal (see section 7).
- Remove the clip from the inner end of the pivot shaft,if equipped (see illustration).
- Unscrew the brake pedal pivot shaft and remove the pedal (see illustration).
- Inspect the pedal pivot shaft seals. If they?re worn, damaged or appear to have been leaking, pry them out and press in new ones.
Installation is the reversal of the removal steps, with the following additions:
- Lubricate the pedal shaft or pivot bolt O-rings and the pivot hole with multipurpose grease.
- Tighten the pedal pivot shaft to the torque listed in this Chapter?s specifications.
- Use a new cotter pin.
- Refer to Chapter 1 and adjust the brake pedal height.
Subject: 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Yamaha YZ, WR 4-Stroke Motocross and Off-Road service, maintenance, repair. ISBN-10: 156392689X | ISBN-13: 9781563926891 | Haynes 2689