Yamaha MX250 - Checking the Crankshaft; Checking the Connecting Rod Oil Clearance

3-41
1
2
3
4
5
6
7
8
9
10
ENGINE
PISTON, CAMSHAFT, CRANKCASE, AND CRANKSHAFT
CHECKING THE CRANKSHAFT
1.
Check:
• Crankshaft sprocket “1”
Damage/wear  Replace the crankshaft.
2.
Measure:
• Crankshaft runout limit
Out of specification  Replace.
Use a dial gauge.
3.
Measure:
• Crank pin outside diameter “a”
Out of specification  Replace.
Use a micrometer.
CHECKING THE CONNECTING ROD OIL
CLEARANCE
TIP
Measure the oil clearance if replacing the crankshaft or
connecting rod.
1.
Place a piece of Plastigauge® “1” on the crank pin
horizontally.
TIP
Wipe off oil thoroughly from the crankshaft, connecting
rod, and connecting rod cap.
1
Dial indicator gauge:
YU-A8428
Dial gauge:
90890-03097
Runout limit:
0.8 mm (0.0315 in)
a
Crank pin outside diameter:
33.969–33.984 mm (1.3374–1.3380 in)
Limit:
33.9 mm (1.3346 in)
1