Checking The Big End Oil Clearance - Yamaha F150A Service Manual

Crankshaft journal diameter "a":
51.980–52.000 mm
(2.0465–2.0472 in)
Crankpin diameter "b":
49.980–50.000 mm
(1.9677–1.9685 in)
Crankpin width "c":
22.000–22.100 mm
(0.8661–0.8701 in)
2. Measure the crankshaft runout.
Crankshaft runout: 0.03 mm (0.0012 in)

Checking the big end oil clearance

1. Clean the crankpin bearings, connecting
rod, connecting rod cap, and crankpin.
2. Install the crankpin bearings "1" into the
connecting rod "2" and connecting rod
cap "3".
TIP:
Install the crankpin bearings in the original
positions.
2
1
3
3. Place a piece of Plastigauge (PG-1) on
the crankpin, parallel to the crankshaft.
TIP:
Do not place the Plastigauge (PG-1) over the
oil hole in the crankpin of the crankshaft.
4. Install the connecting rod "1" and con-
necting rod cap "2" onto the crankpin.
TIP:
• When checking the oil clearance, reuse the
removed connecting rod bolts.
• Make sure that the marks "a" on the con-
necting rod "1" and connecting rod cap "2"
face toward the flywheel magnet end of the
crankshaft.
• Do not turn the connecting rod until the big
end oil clearance measurement has been
completed.
2
5. Tighten the connecting rod bolts "1" to
the specified torques in 3 stages.
7-67
Crankcase
0
1
1
2
3
4
5
6
7
1
8
a
a
9
10
A