CYLINDER AND PISTON
5-35
d. If out of specification, replace the cylinder,
the piston, and the piston rings as a set.
e. Calculate the piston-to-cylinder clearance
with the following formula.
f. If out of specification, replace the cylinder,
the piston, and the piston rings as a set.
EAM30098
CHECKING THE PISTON RINGS
1. Measure:
•
Piston ring side clearance
Out of specification
Replace the piston
and piston rings as a set.
TIP
Before measuring the piston ring side clearance,
eliminate any carbon deposits from the piston
ring grooves and piston rings.
2. Install:
•
Piston ring
(into the cylinder)
TIP
Use the piston crown to level the piston ring near
bottom of cylinder “a”, where cylinder wear is
lowest.
3. Measure:
•
Piston ring end gap
Out of specification
Replace the piston
ring.
TIP
The oil ring expander spacer’s end gap cannot
be measured. If the oil ring rail’s gap is exces-
sive, replace all three piston rings.
EAM30099
CHECKING THE PISTON PIN
1. Check:
•
Piston pin
Blue discoloration/grooves
Replace the
piston pin and then check the lubrication sys-
tem.
Diameter
76.955–76.970 mm (3.0297–
3.0303 in)
Measuring point (from piston
skirt bottom)
4.0 mm (0.16 in)
Piston-to-cylinder clearance =
Cylinder bore “C” - Piston diameter
Piston-to-cylinder clearance
0.030–0.055 mm (0.0012–0.0022
in)
Ring side clearance
0.030–0.065 mm (0.0012–0.0026
in)
Side clearance limit
0.115 mm (0.0045 in)
b
a
Piston ring
Top ring
End gap (installed)
0.15–0.25 mm (0.0059–0.0098 in)
End gap limit
0.50 mm (0.0197 in)
b. Upper of cylinder
a
b
Содержание YZ 2020 Series
Страница 6: ...EAM20162 YAMAHA MOTOR CORPORATION U S A YZ MOTORCYCLE LIMITED WARRANTY...
Страница 10: ......
Страница 50: ...ENGINE SPECIFICATIONS 2 5 Throttle grip free play 3 0 6 0 mm 0 12 0 24 in...
Страница 62: ...CABLE ROUTING DIAGRAM 2 17 EAM20152 CABLE ROUTING DIAGRAM Frame and engine left side view...
Страница 64: ...CABLE ROUTING DIAGRAM 2 19 Frame and engine right side view...
Страница 66: ...CABLE ROUTING DIAGRAM 2 21 Handlebar front view...
Страница 68: ...CABLE ROUTING DIAGRAM 2 23 Frame and engine top view...
Страница 70: ...CABLE ROUTING DIAGRAM 2 25 Frame and battery top view...
Страница 72: ...CABLE ROUTING DIAGRAM 2 27 Rear brake right side view...
Страница 74: ...CABLE ROUTING DIAGRAM 2 29...
Страница 112: ...ELECTRICAL SYSTEM 3 36...
Страница 154: ...HANDLEBAR 4 40 Throttle grip free play 3 0 6 0 mm 0 12 0 24 in...
Страница 167: ...FRONT FORK 4 53 1...
Страница 187: ...INSTALLING THE TRANSMISSION 5 75...
Страница 190: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 5 3 1 Oil filter element 2 Oil pump...
Страница 191: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 5 4 1 Intake camshaft 2 Exhaust camshaft...
Страница 192: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 5 5 1 Camshaft 2 Oil pressure check bolt 3 Oil pump 4 Oil filter element...
Страница 246: ...SHIFT SHAFT 5 59 TIP Align the punch mark a on the shift shaft with the punch mark b in the shift pedal 1 1 2 2 a b...
Страница 274: ...WATER PUMP 6 9...
Страница 284: ...THROTTLE BODY 7 9...
Страница 287: ......
Страница 288: ...IGNITION SYSTEM 8 1 EAM20142 IGNITION SYSTEM EAM30277 CIRCUIT DIAGRAM...
Страница 292: ...ELECTRIC STARTING SYSTEM 8 5 EAM20143 ELECTRIC STARTING SYSTEM EAM30279 CIRCUIT DIAGRAM...
Страница 296: ...CHARGING SYSTEM 8 9 EAM20144 CHARGING SYSTEM EAM30282 CIRCUIT DIAGRAM...
Страница 299: ...CHARGING SYSTEM 8 12...
Страница 300: ...SIGNALING SYSTEM 8 13 EAM20154 SIGNALING SYSTEM EAM30348 CIRCUIT DIAGRAM...
Страница 304: ...FUEL INJECTION SYSTEM 8 17 EAM20145 FUEL INJECTION SYSTEM EAM30284 CIRCUIT DIAGRAM...
Страница 328: ...FUEL PUMP SYSTEM 8 41 EAM20146 FUEL PUMP SYSTEM EAM30287 CIRCUIT DIAGRAM...
Страница 360: ...SELF DIAGNOSTIC FUNCTION AND DIAGNOSTIC CODE TABLE 9 15...
Страница 370: ...CHASSIS 10 9...
Страница 372: ......
Страница 375: ...YZ250FXL1 2020 WIRING DIAGRAM BAJ 28199 10_WD indd 1 2019 07 10 9 35 33...
Страница 376: ...YZ250FXL1 2020 WIRING DIAGRAM BAJ 28199 10_WD indd 2 2019 07 10 9 35 33...