Husqvarna 331RB, Workshop Manual

Page: 23 / 48

7.7 Ignition system
7.7.1 Introduction
The engine has an electronic ignition system fully
without moving parts. A defective component cannot be
repaired, but must be replaced by a new component.
If the engine does not fire, the ignition module can be
damaged. Before you replace the ignition module, do
the tests that follow.
7.7.2 To examine the spark plug
CAUTION: Always use the recommended spark
plug type. Incorrect spark plug type can cause
damage to the product.
• Examine the spark plug if the engine is low on
power, is not easy to start or does not operate
correctly at idle speed.
• To decrease the risk of unwanted material on the
spark plug electrodes, obey these instructions:
a) Make sure that the idle speed is correctly
adjusted.
b) Make sure that the fuel mixture is correct.
c) Make sure that the air filter is clean.
• If the spark plug is dirty, clean it and make sure that
the electrode gap is correct, refer to Technical data
on page 46.
• Replace the spark plug if it is necessary.
7.7.3 To do a spark test of the ignition module
1. Disconnect the spark plug cable from the spark plug.
2. Disconnect the spark plug from the cylinder.
3. Connect the ignition tester to the spark plug cap and
ground the clip to the cylinder.
4. Use the knob to adjust the distance between the 2
electrodes. Set the distance to 6 mm.
Note: 6 mm is 6 marks on the scale.
5. Pull the starter rope handle with force. If the ignition
module operates correctly, there is a clear blue
spark between the electrodes. If there is no spark,
examine the spark plug cable.
7.7.4 To examine the spark plug cable
If there is no spark when you do a spark test of the
ignition module, you must examine the spark plug cable.
1. Remove the ignition module. Refer to
To
disassemble the ignition system on page 25.
2. Remove the spark plug cable and the spring from
the spark plug cap.
1281 - 001 - Repair instructions - 23