2000 YAMAHA YZ426F fuel

ENG

4 - 3
EXHAUST PIPE AND SILENCER
EC4S0000
EXHAUST PIPE AND SILENCER
Extent of removal:
1
Silencer removal
2
Exhaust pipe removal
Extent of removal Order Part name Q’ty Remarks
EXHAUST PIPE AND
SILENCER REMOVAL
Preparation for removal Side cover (right) Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
1 Bolt (clamp) 1
2 Bolt (silencer) 2
3 Silencer 1
4 Clamp 1
5 Nut (exhaust pipe) 1
6 Bolt (exhaust pipe) 2
7 Exhaust pipe 1
8Gasket
1
2
1
2

ENG

4 - 4
RADIATOR
EC450001
RADIATOR
Extent of removal:
1
Radiator removal
Extent of removal Order Part name Q’ty Remarks
RADIATOR REMOVAL
Preparation for removal Drain the coolant. Refer to “COOLANT REPLACEMENT”
section in the CHAPTER 3.
Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Exhaust pipe Refer to “EXHAUST PIPE AND
SILENCER” section.
1 Engine guard 1
2 Panel 2
3 Clamp 8
4 Radiator (right) 1
5 Hose 2 1
6 Hose 3 1
7 Hose 4 1
8 Pipe 2/O-ring 1/1
9 Radiator breather hose 1
10 Radiator (left) 1
11 Hose 1 1
12 Pipe 1/O-ring 1/1
1

ENG

4 - 7
CARBURETOR
CARBURETOR
Extent of removal:
1
Carburetor removal
Extent of removal Order Part name Q’ty Remarks
CARBURETOR REMOVAL
Preparation for removal Fuel tank Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
1 Band 1
2 TPS coupler 1
3 Throttle cable cover 1
4 Throttle cable 2
5 Clamp (air cleaner joint) 1 Loosen the screw (air cleaner joint).
6 Clamp (carburetor joint) 2 Loosen the screws (carburetor joint).
7 Carburetor 1
8 Carburetor joint 1
1

4 - 10
ENGCARBURETOR
EC466020
HANDLING NOTE
CAUTION:
Do not loosen the screws {TPS (throttle
position sensor)} 1 except when changing
the TPS (throttle position sensor) due to
failure because it will cause a drop in
engine performance.
EC463000
REMOVAL POINTS
Pilot screw
1. Remove:
lPilot screw 1
NOTE:
To optimize the fuel flow at a small throttle
opening, each machine’s pilot screw has been
individually set at the factory. Before removing
the pilot screw, turn it in fully and count the
number of turns. Record this number as the
factory-set number of turns out.
EC464000
INSPECTION
EC464110
Carburetor
1. Inspect:
lCarburetor body
Contamination ® Clean.
NOTE:
lUse a petroleum based solvent for cleaning.
Blow out all passages and jets with com-
pressed air.
lNever use a wire.

ENG
4 - 17
CAMSHAFTS
CAMSHAFTS
CYLINDER HEAD COVER
Extent of removal:1 Cylinder head cover removal
Extent of removal Order Part name Q’ty Remarks
CYLINDER HEAD COVER
REMOVAL
Preparation for removal Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Radiator Refer to “RADIATOR” section.
Carburetor Refer to “CARBURETOR” section.
1 Spark plug cap 1
2 Engine upper bracket (right) 1
3 Engine upper bracket (left) 1
4 Cylinder head breather hose 1
5 Oil tank breather hose 1
6 Bolt (cylinder head cover) 2
7 Cylinder head cover 1
8 Gasket 1
9 Timing chain guide (upper) 1
1

ENG

4 - 24
CYLINDER HEAD
CYLINDER HEAD
CYLINDER HEAD
Extent of removal:
1
Cylinder head removal
Extent of removal Order Part name Q’ty Remarks
CYLINDER HEAD REMOVAL
Preparation for removal Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Exhaust pipe and silencer Refer to “EXHAUST PIPE AND
SILENCER” section.
Radiator Refer to “RADIATOR” section.
Carburetor Refer to “CARBURETOR” section.
Camshaft Refer to “CAMSHAFTS” section.
1 Decompression cable 1
2 Cable guide 1
3 Bolt 1
4 Decompression shaft 1
5 Oil delivery pipe 1
6 Nut (M6) 2
7 Nut (M8) 2
8 Bolt (L = 150 mm) 2
9 Bolt (L = 160 mm) 2
10 Cylinder head 1
1

ENG
4 - 67
CDI MAGNETO
EC4L0000
CDI MAGNETO
Extent of removal:1 CDI magneto removal
Extent of removal Order Part name Q’ty Remarks
CDI MAGNETO REMOVAL
Preparation for removal Seat and fuel tankRefer to “SAET, FUEL TANK AND SIDE
COVERS” section.
Bolt [radiator (left)]
Disconnect the CDI magneto lead.Refer to “RADIATOR” section.
1 Shift pedal 1
2 Crankcase cover (left) 1
3 Gasket 1
4 Dowel pin 2
5 Nut (rotor) 1 Use special tool.
Refer to “REMOVAL POINTS”.
6 Rotor 1
7 Stator 1
8 Woodruff key 1
1

ENG
4 - 71
ENGINE REMOVAL
EC4M0000
ENGINE REMOVAL
Extent of removal Order Part name Q’ty Remarks
ENGINE REMOVAL
Preparation for removal Hold the machine by placing the
suitable stand under the frame.
Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Carburetor Refer to “CARBURETOR” section.
Exhaust pipe and silencer Refer to “EXHAUST PIPE AND
SILENCER” section.
Clutch cable Disconnect at engine side.
Decompression cable and guide Disconnect at engine side.
Radiator Refer to “RADIATOR” section.
Shift pedal Refer to “CDI MAGNETO” section.
Cylinder head breather hose and
oil tank breather hoseRefer to “CAMSHAFTS” section.
Drain the engine oil Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Spark plug cap
Disconnect the CDI magneto lead.
WARNING
Support the machine securely so there is nodanger of it falling over.