Troubleshooting - Cub Cadet Challenger Series Service Manual

When troubleshooting or diagnosing a problem on a UV, it is always good to use a
systematic approach to solving the issue. There are 3 main things to look for to have a
running motor.
 A fuel/air mixture being delivered to the cylinder.
 Compression inside of the cylinder.
 A timed spark to ignite the compressed fuel/air mix.
Without any one of these, the combustion process cannot take place.
Before any testing, be sure you have a known good battery source.
Spark Test
Perform a spark test to determine if the ignition system is producing an adequate spark.
This test should be performed with a spark tester. A spark tester looks like a spark plug
with an adjustable gap between the center electrode and a grounded base. Because
the voltage required to jump the spark tester gap is sufficiently larger than that of a
normally gapped spark plug, the test results are more accurate than with a spark plug.
Do not assume that because a spark jumped across a spark plug gap, the ignition
system is working correctly. Perform this test on the engine when it is both cold and hot,
if possible. If the test results are positive for each test, the ignition system is working
correctly.
Caution:
After removing the direct ignition coil or spark plug cap, and before removing the
spark plug in Step 1, clean the area around the spark plug with compressed air.
Dirt that falls into the cylinder causes rapid engine wear.
1. Disconnect the direct ignition coil or spark plug cap. Check for the presence of water.
2. Visually inspect the spark plug for damage.
3. Connect a spark tester to the direct ignition coil or spark plug cap. Ground the spark
tester base (or spark plug) to a good ground. Position the spark tester or spark plug
firing tip away from the open spark plug hole. Position the spark tester so the
electrode is visible.
Warning:
Mount the spark tester or spark plug away from the spark plug hole in the
cylinder. If the engine is flooded, do not perform this test. The spark tester
can ignite fuel ejected through the spark plug hole.
4. Shift the transmission into neutral.
Warning:
Do not hold the spark tester, spark plug or connector while turning over the
motor or a serious shock may result.

Troubleshooting

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