Yamaha F2 5 Service Manual

							69M3E11
POWR
1
2
3
4
5
6
7
8
9
Power unit
Special service tools ..................................................................................... 5-1
Power unit ....................................................................................................... 5-3
Checking the compression pressure ......................................................... 5-7
Disassembling the manual starter ............................................................. 5-7
Checking the spiral spring ......................................................................... 5-8
Assembling the manual starter .................................................................. 5-8
Removing the power unit ......................................................................... 5-10
Cylinder head ............................................................................................... 5-12
Removing the cylinder head .................................................................... 5-14
Checking the rocker arms........................................................................ 5-15
Checking the push rod guide ................................................................... 5-15
Checking the push rods ........................................................................... 5-15
Checking the valve springs...................................................................... 5-15
Checking the valves ................................................................................ 5-16
Checking the valve guides....................................................................... 5-16
Replacing the valve guides...................................................................... 5-17
Checking the valve seat .......................................................................... 5-18
Refacing the valve seat ........................................................................... 5-18
Checking the cylinder head ..................................................................... 5-20
Installing the valves ................................................................................. 5-21
Cylinder block .............................................................................................. 5-22
Disassembling the cylinder body ............................................................. 5-24
Checking the piston diameter .................................................................. 5-24
Checking the cylinder bore ...................................................................... 5-25
Checking the piston clearance ................................................................ 5-25
Checking the piston rings ........................................................................ 5-25
Checking the piston ring grooves ............................................................ 5-26
Checking the piston ring side clearance .................................................. 5-26
Checking the piston pin boss bore .......................................................... 5-26
Checking the piston pin ........................................................................... 5-27
Checking the connecting rod small end inside diameter ......................... 5-27
Checking the connecting rod big end side clearance .............................. 5-27
Checking the crankshaft .......................................................................... 5-27
Checking the crankpin oil clearance ........................................................ 5-28
Checking the camshaft ............................................................................ 5-29
Checking the valve lifters......................................................................... 5-30
Checking the oil splasher gear ................................................................ 5-30
Disassembling the cylinder block ............................................................ 5-30
Assembling the cylinder block ................................................................. 5-31
Disassembling the crankcase .................................................................. 5-31
Checking the oil seal housing .................................................................. 5-32
Assembling the crankcase....................................................................... 5-32
Assembling the piston and cylinder block................................................ 5-33
Installing the power unit ........................................................................... 5-36 
						

							POWRPower unit
5-169M3E11
Special service tools5
Compression gauge
90890-03160
Flywheel holder
90890-06522
Flywheel puller
90890-06521
Valve spring compressor
90890-04019
Valve spring compressor attachment
90890-06320Valve guide remover/installer
90890-06801
Valve guide reamer
90890-06804
Valve seat cutter holder
90890-06316
Valve seat cutter
90890-06312, 90890-06315, 90890-06328
Crank stand alignment
90890-03107 
						

							69M3E115-2
1
2
3
4
5
6
7
8
9
Stopper guide plate
90890-06501
Stopper guide stand
90890-06538
Bearing puller
90890-06535
Bearing puller claw 1
90890-06536
Driver rod L3
90890-06652Needle bearing attachment
90890-06613
Driver rod LS
90890-06606
Bearing outer race attachment
90890-06624
Bushing attachment
90890-06649
Piston slider
90890-06843
Special service tools 
						

							POWRPower unit
5-369M3E11
Power unit5
No. Part name Q’ty Remarks
1 Starter case 1
2 Flywheel magnet cover 1
3Spiral spring 1
4 Sheave drum 1
5 Drive pawl 2
6Drive plate 1
7Screw 1
8 Choke knob assembly 1
9 Stopper 1
10 Manual starter handle 1
11 Damper 1
12 Starter rope 1
13 Spring 1
14 Plate 1
15 Bolt 3 M6 
× 60 mm 
						

							69M3E115-4
1
2
3
4
5
6
7
8
9
5
No. Part name Q’ty Remarks
1 TCI unit 1
2 Flywheel magnet 1
3 Starter pulley 1
4 Spark plug 1
5Grommet 1
6 Clamp 1
7Bolt 2 M6 
× 25 mm
8Bolt 1 M6 
× 12 mm
9Nut 1
10 Washer 1
11 Woodruff key 1
12 Spark plug cap 1
Power unit 
						

							POWRPower unit
5-569M3E11
5
No. Part name Q’ty Remarks
1 Power unit 1
2Gasket 1
Not reusable
3 Bottom cowling 1 1
4 Bottom cowling 2 1
5 Carrying handle 1
6Bracket 1
7 Thermostat cover 1
8Gasket 1
Not reusable
9 Thermostat 1
10 Oil filler cap 1
11 O-ring 1
12 Anode 1
13 Screw 1ø5 
× 25 mm
14 Grommet 1
15 Damper 1
16 Dowel 2
17 Fuel cock lever 1 
						

							69M3E115-6
1
2
3
4
5
6
7
8
9
5
No. Part name Q’ty Remarks
18 Screw 1ø5 
× 7 mm
19 Cooling water hose 1
20 Throttle cable 1
21 Bolt 6 M6 
× 36 mm
22 Bolt 4 M6 
× 16 mm
23 Bolt 2 M6 
× 20 mm
24 Bolt 2 M6 
× 20 mm
25 Bolt 3 M6 
× 20 mm
26 Screw 2ø5 
× 13 mm
27 O-ring 1
28 Grommet 4
29 Collar 4
30 Spring nut 2
Power unit 
						

							POWRPower unit
5-769M3E11
Checking the compression pressure
1. Start the engine, warm it up for 5 min-
utes, and then turn it off.
2. Remove the engine shut-off cord from
the engine shut-off switch on the tiller
handle.
3. Remove the grommet and spark plug,
and then install the special service tool to
the spark plug hole.
CAUTION:
Before removing the spark plug, blow
compressed air in the spark plug well to
clear out any dirt or dust that may fall into
the cylinder.
4. Close the fuel cock and air vent screw,
fully open the throttle, pull the starter
rope 3 times, and then check the com-
pression pressure.
NOTE:
Do not pull the choke knob when checking
the compression pressure.
5. If the compression pressure is below
specification, add a small amount of
engine oil to the cylinder, and then check
the pressure again.
NOTE:
If the compression pressure increases,
check the piston and piston rings for wear.
Replace if necessary.
If the compression pressure does not
increase, check the valve clearance,
valves, valve seat, cylinder sleeve, cylinder
head gasket, and cylinder head. Adjust or
replace if necessary.
Disassembling the manual starter
1. Remove the choke knob assembly 1
.
2. Remove the drive plate 2
 and drive
pawls 3
.
 WARNING
The sheave drum can pop out. Hold the
sheave drum with your hand, and then
pull it out.
Compression gauge 1
:
90890-03160
Minimum compression pressure 
(reference data):
700 kPa (7.0 kgf/cm
2, 102 psi)
S69M5060
1
S69M5080
2
3
3 
						

							69M3E115-8
1
2
3
4
5
6
7
8
9
3. Remove the sheave drum 4
.
 WARNING
The spiral spring can pop out. Pull the
starter rope, and then pull out the sheave
drum.
4. Remove the spiral spring 5
 from the
sheave drum.
 WARNING
The spiral spring can pop out. To remove
the spring, cover it with cloths.
5. Remove the starter rope 6
.
Checking the spiral spring
1. Check the spiral spring for cracks, bends,
or damage. Replace if necessary.
Assembling the manual starter
1. Pass the starter rope 1
 through the
starter case 2
, and then install the
starter rope to the sheave drum 3
 and
manual starter handle 4
.
NOTE:
Tie a knot at the end of the starter rope as
shown in the illustration.
Be sure to leave 5–10 mm at the end a
 of
the starter rope.
S69M5090
4
S69M5100
5
S69M5110
6
S69M5120
S69M5B30
a
a
2
3
14
Power unit 
						

							POWRPower unit
5-969M3E11
2. Wind the starter rope 1
 2 times around
the sheave drum 3
 in the direction of the
arrow shown in the illustration.
NOTE:
After winding the starter rope around the
sheave drum, install the starter rope in the
notch b
.
3. Wind the spiral spring 5
.
 WARNING
When winding the spiral spring, cover it
with cloths.
4. Install the spiral spring 5
 into the sheave
drum 3
.
NOTE:
Bend the outer end c
 of the spiral spring
onto the cutout d
 of the sheave drum.
5. Install the sheave drum 3
 into the starter
case 2
.
NOTE:
Install the sheave drum so that the inner end
e
 of the spiral spring can be bent onto the
cutout f
 of the starter case.
6. Install the drive pawls 6
 and drive plate
7
.
7. Pull the starter rope 1
 in the direction of
the arrow shown in the illustration, turn
the sheave drum 3
 3 times, and then
remove the starter rope from the notch
g
.
S69M5B40
1 3
b
1
3
S69M5B50
5
S69M5B60
5
3
c
d
S69M5B70
32
e
f
S69M5B80
7
6
6