Service manual
Table Of Contents
- Inroduction
- Yamaha Motor Corporation, USA YZ/WR Motorcycle Limited Warranty
- How to use this Manual
- Index
- Contents
- Chapter 1 General Information
- Chapter 2 Specifications
- Chapter 3 Regular Inspection and Adjustments
- Chapter 4 Engine
- Seat, Fuel Tank and Side Covers
- Exhaust Pipe and Silencer
- Radiator
- Carburetor and Reed Valve
- Cylinder Head, Cylinder and Piston
- Clutch and Primary Driven Gear
- Kick Axle, Shift Shaft and Primary Drive Gear
- YPVS Govenor
- Water Pump
- CDI Magneto
- Engine Removal
- Crankcase and Crankshaft
- Transmission, Shift Cam and Shift Fork
- Chapter 5 Chassis
- Chapter 6 Electrical
- Chapter 7 Tuning
4-10
ENG
CARBURETOR AND REED VALVE
EC464200
Needle valve
1. Inspect:
9
Needle valve 1
9
Valve seat 2
Grooved wear a → Replace.
Dust b → Clean.
NOTE:
Always replace the needle valve and valve seat
as a set.
EC464301
Throttle valve
1. Check:
9
Free movement
Stick → Repair or replace.
NOTE:
Insert the throttle valve 1 into the carburetor
body, and check for free movement.
EC464401
Jet needle
1. Inspect:
9
Jet needle 1
Bends/Wear → Replace.
9
Clip groove
Free play exists/Wear → Replace.
9
Clip position
Standard clip position:
No.4 Groove
2. Inspect:
9
Main jet 1
9
Main jet holder 2
9
Pilot jet 3
Contamination → Clean.
NOTE:
9
Use a petroleum based solvent for cleaning.
Blow out all passages and jets with com-
pressed air.
9
Never use a wire.
1C3-28199-10 99 04.5.17, 9:21:41 PM