COMPRESSION INSPECTION [MZR 1.3, MZR 1.5]

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Warning
•  Hot engines can cause severe burns. Be careful not to burn yourself during removal/installation of each component.
•  Fuel vapor is hazardous. It can very easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.
•  Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete the "Fuel Line Safety Procedure" when servicing the fuel system. (See BEFORE SERVICE PRECAUTION [MZR 1.3, MZR 1.5].)

1.  Verify that the battery is fully charged. (See BATTERY INSPECTION [MZR 1.3, MZR 1.5].)

2.  Warm up the engine to the normal operating temperature.

3.  Complete the "Fuel Line Safety Procedure", and remove the fuel pump relay. (See BEFORE SERVICE PRECAUTION [MZR 1.3, MZR 1.5].)

4.  Perform the following procedure.

Without set bolt
1.  Remove the fresh-air duct and the air cleaner as a single unit. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)
With set bolt
1.  Set the air cleaner cover out of the way. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)
2.  Remove the fresh-air duct and the air cleaner case as a single unit. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)

5.  Remove the ignition coils. (See IGNITION COIL REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)

6.  Remove all the spark plugs. (See SPARK PLUG REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)

7.  Measure the compression pressure using the following procedure.

(1)  Connect the compression gauge into the spark plug hole.
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(2)  Depress the accelerator pedal.
(3)  Crank the engine and measure the compression pressure.
Compression pressure
MZR 1.3 (Except Miller Cycle Engine)
Standard: 1,461 kPa {14.90 kgf/cm2, 211.9 psi}[300 rpm]
Minimum: 1,023 kPa {10.44 kgf/cm2, 148.4 psi}[300 rpm]
Maximum difference between cylinders: 196.1 kPa {2.0 kgf/cm2, 28.5 psi} a or less
MZR 1.3 (Miller Cycle Engine)
Standard: 1,324 kPa {13.50 kgf/cm2, 192.0 psi}[300 rpm]
Minimum: 927 kPa {10.44 kgf/cm2, 148.4 psi}[300 rpm]
Maximum difference between cylinders: 196.1 kPa {2.0 kgf/cm2, 28.5 psi} a or less
MZR 1.5
Standard: 1,520 kPa {15.50 kgf/cm2, 220.5 psi}[300 rpm]
Minimum: 1,064 kPa {10.85 kgf/cm2, 154.3 psi}[300 rpm]
Maximum difference between cylinders: 196.1 kPa {2.0 kgf/cm2, 28.5 psi} a or less
(4)  Perform Steps (1) to (3) all of the cylinders.
(5)  If it is less than the minimum specification, or there is a cylinder with a compression value that varies from that of other cylinders by 196.1 kPa {2.0 kgf/cm2, 28.5 psi} or more perform Steps (1) to (3) adding a small quantity of engine oil from the spark plug hole.
•  If the pressure increases by adding the engine oil, the piston ring or the cylinder surface is worn, or they are damaged. Perform overhaul servicing.
•  If the pressure does not increase, valve seizure, valve attachment failure, or pressure leaking from the cylinder head gasket might be occurring. Perform overhaul servicing.

8.  Install the spark plugs. (See SPARK PLUG REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)

9.  Install the ignition coils. (See IGNITION COIL REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)

10.  Install the fresh-air duct and the air cleaner component as a single unit. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZR 1.3, MZR 1.5].)

11.  Install the fuel pump relay. (See BEFORE SERVICE PRECAUTION [MZR 1.3, MZR 1.5].)