Checking The Cylinder Head; Checking The Oil Pump; Installing The Valves - Yamaha F15B Service Manual

POWR

Checking the cylinder head

1. Eliminate carbon deposits from the com-
bustion chambers and check for deterio-
ration.
2. Check the cylinder head warpage using a
straightedge 1 and thickness gauge 2
in five directions as shown. Replace if out
of specification
1
Cylinder head warpage limit:
0.10 mm (0.0039 in)

Checking the oil pump

1. Removing the screws 1 and disassem-
ble the oil pump.
5-31
Power unit
6D450810
2
6D450820
1
6D450531
2. Measure the oil pump rotor clearances as
shown. Replace if out of specification.
a
a
c
Clearance a:
0.100–0.150 mm (0.0039–0.0059 in)
Clearance b:
0.040–0.140 mm (0.0016–0.0055 in)
Clearance c:
0.030–0.090 mm (0.0012–0.0035 in)

Installing the valves

1. Install the new valve stem seal 1 to the
valve guide, and then apply engine oil to
the valve guide.
1
E
c
b
6D450840
b
6D450840
6D450850
6D45F11