Excelsior-HENDERSON HCX 1999, Service Handbook

Page: 250 / 474

6-4
6999-0003 7/15/99
CYLINDER HEAD/CAM DRIVE
(StepNumberStart)
(StepNumber)
(StepNumber)
COMPRESSION TEST
Notice
The ECM will record fault codes if the main switch is
placed in the
On position or if the engine is cranked while
certain electrical components are disconnected. The
ECM automatically clears these fault codes after the
components are reconnected
(see Managing System
diagnostics page 4-10) . Refer to the Examinator
Handbook for information about clearing the fault codes
using the Examinator™ diagnostic tool.
1. Warm the engine to normal operating temperature, then
stop the engine.
2. Disconnect the ignition coil wires and remove the ignition
coils.
3. Blow the area around the spark plugs clean with air.
4. Remove the spark plugs.
5. Connect a compression gauge to the front cylinder.
1. COMPRESSION GAUGE
6. Make sure the transmission is in neutral.
7. Make sure the engine Run/Stop switch is set to RUN .
8. Turn the throttle control grip all the way open and crank
the engine with the starter until the reading on the
compression gauge stops rising (5 or 6 full compression
strokes).
9. Note the gauge reading, reset the compression gauge
and repeat the test.
1. RUN/STOP SWITCH IN
RUN POSITION
2. THROTTLE ALL THE WAY
OPEN
10. Connect the compression gauge to the rear cylinder.
Repeat steps 6 thru 9 for the rear cylinder.
Standard: 125 - 175 psi
11. Compare the front cylinder reading to the rear cylinder
reading and determine the degree of difference.
Standard: 0 - 10%
12. If compression readings are high, assume heavy carbon
deposits have formed on the piston or in the combustion
chamber.
1. COMPRESSION GAUGE