Measuring The Compression Pressure

ENGINE

                                                            EAS20710

                                                            MEASURING THE COMPRESSION
                                                            PRESSURE
                                                            The following procedure applies to all of the cyl-
                                                            inders.
                                                        NOTE:
                                                            Insufficient compression pressure will result in a
                                                            loss of performance.
                                                            1. Measure:
5. Install:                                                  • Valve clearance
 • Fuel tank                                                   Out of specification → Adjust.
   Refer to “FUEL TANK” on page 7-1.                           Refer to “ADJUSTING THE VALVE CLEAR-
6. Check:                                                      ANCE” on page 3-6.
 • Ignition timing                                          2. Start the engine, warm it up for several min-
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼                               utes, and then turn it off.
a. Start the engine, warm it up for several min-            3. Remove:
   utes, and then let it run at the specified en-            • Rider seat
   gine idling speed.                                          Refer to “GENERAL CHASSIS” on page 4-1.
                                                             • Fuel tank
           Engine idling speed                                 Refer to “FUEL TANK” on page 7-1.
            1000–1100 r/min                                  • T-bar
                                                               Refer to “GENERAL CHASSIS” on page 4-1.
b. Check that pointer “a” on the pickup rotor cov-          4. Disconnect the all spark plug caps.
   er is within the firing range “b” on the pickup
                                                            5. Remove:
   rotor.                                                    • Spark plug
   Incorrect firing range → Check the ignition              ECA13340

   system.                                                  CAUTION:
                                                            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.
                                                            6. Install:
                                                             • Compression gauge “1”

                                                                           Compression gauge
                                                                            90890-03081
                                                                           Engine compression tester
NOTE:
                                                                            YU-33223
The ignition timing is not adjustable.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
7. Tighten:                                                            1
 • Timing mark accessing plug
   (along with the copper washer New )

           Timing mark accessing plug
     T.
      R.
            15 Nm (1.5 m·kg, 11 ft·lb)

8. Install:
 • T-bar                                                    7. Measure:
 • Rider seat                                                • Compression pressure
 • Right side cowling                                          Out of specification → Refer to steps (c) and
   Refer to “GENERAL CHASSIS” on page 4-1.                     (d).

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