Engine Inspection; Measuring The Compression Pressure - Yamaha FZ09E Service Manual

EA$1AC1506
ENGINE INSPECTION
EA$2011 0
MEASURING THE COMPRESSION
PRESSURE
The following procedure applies to all of the cyl-
inders.
TIP - - - - - - - - - - - - - : - -
lnsufficient compression pressure will result in a
loss of performance.
1. Measure:
• Valve clearance
Out of specification -+Adjust.
Refer to "ADJUSTING THE VALVE CLEAR -
ANCE" on page 3·5.
2. Start the engine, warm it up for several min·
utes, and then turn it off.
3. Remove:
• Rider seat
Refer to "GENERAL CHASSIS" on page 4· 1.
• Fuel tank
Refer to "FUEL TANK" on page 7-1.
• Air filter case
Refer to "GENERAL CHASSIS" on page 4-1.
• Air cut-off valve
Refer to "AIR INDUCTION SYSTEM" on
page 7-1 5.
• Ignition coils
• Spar1< plugs
Refer to "CAMSHAFTS" on page 5·9.
NOTICE _ _ _ _ _ _ _ _ _ _ _ _
Before removing the spark plugs, use com·
pressed air to blow away any dirt accumulat·
ed in the spark plug wells to prevent it from
falling into the cylinders.
4. Install:
• Compression gauge "1"
• Extension "2"
Compression gauge
90890-03081
Engine compression tester
YU-33223
Extension
90890-04136
5-1
ENGINE INSPECTION
1
2
5. Measure:
• Compression pressure
Out of specification -+ Refer to steps (c) and
(d).
Standard compression pressure
(at sea level)
1530 kPa/680 r/min (15.3
kgf/cm
2
/680 r/min, 217.6 psi/680
r/min)
Minimum-maximum
1330-171 O kPa/680 r/min
(13.3-17.1 kgf/cm
2
/680 r/min,
189.2-243.2 psi/680 r/min)
• •••••••••••••••••••••••••••••••
a . Set the main switch to "ON".
b. With the throttle wide open, crank the engine
until the reading on the compression gauge
stabilizes.
A
WARNING
To prevent sparking the plug, remove all ig-
nition coil couplers and fuel injector cou-
plers before cranking the engine.
TIP - - - - - - - - - - - - -
The difference in compression pressure be-
tween cylinders should not exceed 100 kPa (1
kg/cm
2
,
15 psi).
c. If the compression pressure is above the
maximum specification, check the cylinder
head, valve surfaces and piston crown for
carbon deposits.
Carbon deposits -+ Eliminate.
d. If the compression pressure is below the min-
imum specification, pour a teaspoonful of en-
gine oil into the spark plug bore and measure
again.
Reier to the following table.