2001 YAMAHA WR 426F Owners Manual

Page 417 of 762

YAMAHA WR 426F 2001  Owners Manual  
4 - 41
ENG
 
CYLINDRE ET PISTON  
ZYLINDER UND KOLBEN  
CILINDRO Y PISTÓN  
ZYLINDER UND KOLBEN 
ZYLINDER UND KOLBEN 
Demontage-Arbeiten:  
1  
 Zylinder demontieren  
2  
 Kolben demontieren 
Demo

Page 418 of 762

YAMAHA WR 426F 2001  Owners Manual 4 - 42
ENGCYLINDER AND PISTON
REMOVAL POINTS
Piston
1. Remove:
lPiston pin clips 1 
lPiston pin 2 
lPiston 3 
NOTE:
lPut identification marks on each piston head
for reference during reinstallation.
l

Page 419 of 762

YAMAHA WR 426F 2001  Owners Manual ENG
 
4 - 42 
CYLINDRE ET PISTON  
ZYLINDER UND KOLBEN  
CILINDRO Y PISTÓN 
AUSBAU
Kolben  
1. Demontieren: 
l 
Kolbenbolzen-Sicherungs-
ringe   
1  
  
l 
Kolbenbolzen   
2  
  
l 
Kolben   
3  
 
H

Page 420 of 762

YAMAHA WR 426F 2001  Owners Manual 4 - 43
ENGCYLINDER AND PISTON
Cylinder bore “C”WR426F:
95.00 ~ 95.01 mm
(3.7402 ~ 3.7406 in)
WR400F:
92.00 ~ 92.01 mm
(3.6220 ~ 3.6224 in)
Taper limit “T” 0.05 mm (0.002 in)
Out of round “R

Page 421 of 762

YAMAHA WR 426F 2001  Owners Manual ENG
 
4 - 43 
CYLINDRE ET PISTON 
ZYLINDER UND KOLBEN 
CILINDRO Y PISTÓN 
Zylinderboh-
rung “C”WR426F:
95,00– 
95,01 mm
WR400F:
92,00–
92,01 mm
Konizität “T” 0,05 mm
Unrundheit 
“R”0

Page 422 of 762

YAMAHA WR 426F 2001  Owners Manual 4 - 44
ENGCYLINDER AND PISTON
3rd step:
lCalculate the piston-to-cylinder clearance
with following formula:
Piston-to-cylinder clearance =
Cylinder bore “C” –
Piston skirt diameter “P”
Pisto

Page 423 of 762

YAMAHA WR 426F 2001  Owners Manual ENG
4 - 44
CYLINDRE ET PISTON
ZYLINDER UND KOLBEN
CILINDRO Y PISTÓN
3. Schritt
lKolbenlaufspiel nach der fol-
genden Formel berechnen:
Kolbenlaufspiel = 
Zylinderbohrung “C” – 
Kolbenschaftdurc

Page 424 of 762

YAMAHA WR 426F 2001  Owners Manual 4 - 45
ENGCYLINDER AND PISTON
3. Measure:
lRing end gap 
Out of specification ® Replace.
NOTE:
You cannot measure the end gap on the
expander spacer of the oil control ring. If the oil
control ring r