Yamaha F225F, Service Manual

Page: 284 / 576

7-1
Power unit
POWR
Power unit (check and
adjustment)
Checking the compression pressure
1. Start the engine, warm it up for 5–10 min-
utes, and then stop it.
2. Remove the clip from the engine shut-off
switch.
3. Disconnect the fuel injector couplers.
4. Remove the intake silencer.
5. Remove the ignition coils and spark
plugs.
NOTICE: Before removing the
spark plugs, remove any dirt or dust
in the spark plug wells that could fall
into the cylinders.
6. Install the special service tools
a
and
b
into the spark plug hole.
7. Crank the engine until the reading on the
compression gauge stabilizes, and then
measure the compression pressure.
8. Remove the special service tools
a
and
b
.
9. Tighten the spark plugs to the specified
torque.
10. Install the ignition coils.
11. Connect the fuel injector couplers.
Checking the oil pressure
1. Connect the YDIS to display “Oil pres-
sure.”
2. Start the engine and warm it up until the
engine idle speed stabilizes at 650–750
r/min.
3. Measure the oil pressure.
Checking the pulser coil air gap
Do not turn the flywheel magnet counter-
clockwise. Otherwise, the water pump
impeller could be damaged.
1. Remove the intake silencer.
2. Turn the flywheel magnet clockwise to
align a protrusion
a
on the flywheel
magnet with the protrusion
b
on the
pulser coil.
3. Measure the pulser coil air gap
c
.
Compression gauge
a
: 90890-03160
Compression gauge extension
b
:
90890-06563
Minimum compression pressure
(reference data):
700.0 kPa (7.0 kgf/cm
2
, 101.5 psi)
at 20 °C (68 °F)
Spark plug: 28 N·m (2.8 kgf·m, 20.7 ft·lb)
a
b
Oil pressure (reference data):
350.0 kPa (3.50 kgf/cm
2
, 50.8 psi) at
60 °C (140 °F) with SL 10W-30
engine oil and at 700 r/min
590.0 kPa (5.90 kgf/cm
2
, 85.6 psi) at
68 °C (154 °F) with SL 10W-30
engine oil and at 3000 r/min
Pulser coil air gap
c
:
0.4–1.1 mm (0.016–0.043 in)
c
a b