Kohler Comand Pro CH1000 Service Manual page 60

Section 7
Electrical System and Components
Test 1. Isolate and Verify the Trouble is Within the
Engine Ignition System
1. Locate the connectors where the wiring harnesses
from the engine and equipment are joined.
Separate the connectors and remove the white
kill lead from the engine connector. Rejoin the
connectors and position or insulate the kill
lead terminal so it cannot touch ground. Try to
start the engine to verify whether the reported
problem is still present.
NOTE: If the engine starts or runs during any of
the testing, you may need to ground the
kill lead to shut it down. Because you have
interrupted the kill circuit, it may not stop
using the switch.
a. If the problem goes away, the electrical
system on the equipment is suspect. Check
the key switch, wires, connections, safety
interlocks, etc.
b. If the problem persists, the condition is
associated with the ignition or electrical
system of the engine. Leave the kill lead
isolated until all testing is completed.
c. Identify the white kill lead of the engine
wiring harness connector. Establish a
connection to a known good ground
location. The engine should kill completely.
If not, or only one cylinder is aff ected, go
to Test 4, but also check the white kill lead
connection for the aff ected DSAI module.
Test 2. Test for Spark
1. With the engine stopped, disconnect one spark
plug lead. Connect the spark plug lead to
post terminal of spark tester (Kohler Part No.
25 455 01-S), and att ach tester clip to a good
engine ground.
NOTE: If two testers are available, testing can be
performed simultaneously for both cylinders.
However, if only one tester is available, two
individual tests must be performed. The side
not being tested must have the spark plug
lead connected or grounded. Do not crank
the engine or perform tests with one spark
plug lead disconnected and not grounded, or
permanent system damage may occur.
2. Crank the engine over, establishing a minimum
of 550-600 RPM, and observe tester(s) for spark.
3. Repeat the spark test on the opposite cylinder if
cylinders are being tested individually.
7.8
a. If both cylinders have good spark but
the engine runs poorly, or existing plug
condition or appearance is questionable,
install new spark plugs gapped at 0.76 mm
(0.030 in.), and retest engine performance. If
problem persists, go to Test 3.
b. If one cylinder had good spark but the other
cylinder had no spark, or intermitt ent spark,
go to Test 4.
c. If there was spark on both cylinders but
power is suspect, go to Test 3.
Test 3. Check for Timing Advance
1. Make a line near the edge of the fl ywheel screen
with a marking pen, chalk, or narrow tape. See
Figure 7-7.
Flywheel Screen Mark Flywheel Screen
Figure 7-7. Mark For Timing Advance.
2. Connect an automotive timing light to the
cylinder that had good spark.
3. Run the engine at idle and use the timing light
beam to locate the line on the screen. Draw a line
on the blower housing next to the line on the
screen. Accelerate to full thrott le and watch for
movement of the line on the screen relative to the
line on the blower housing. If both cylinders had
good spark, repeat the test on the other cylinder.
See Figure 7-8.
Mark