Power Unit; Power Unit (Check And Adjustment); Checking The Compression Pressure; Checking The Oil Pressure - Yamaha F225F Service Manual

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.
a
Compression gauge a: 90890-03160
Compression gauge extension b:
90890-06563
7. Crank the engine until the reading on the
compression gauge stabilizes, and then
measure the compression pressure.
Minimum compression pressure
(reference data):
700.0 kPa (7.0 kgf/cm
at 20 °C (68 °F)
8. Remove the special service tools a and
b.
9. Tighten the spark plugs to the specified
torque.
Spark plug: 28 N·m (2.8 kgf·m, 20.7 ft·lb)
7-1

Power unit

b
2
, 101.5 psi)
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.
Oil pressure (reference data):
350.0 kPa (3.50 kgf/cm
60 °C (140 °F) with SL 10W-30
engine oil and at 700 r/min
590.0 kPa (5.90 kgf/cm
68 °C (154 °F) with SL 10W-30
engine oil and at 3000 r/min

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.
a b
c
Pulser coil air gap c:
0.4–1.1 mm (0.016–0.043 in)
2
, 50.8 psi) at
2
, 85.6 psi) at