Ignition System - Husqvarna W21 Operator's Manual

General Recommendations
The warranty on this lawn mower does not cover
items that have been subjected to operator abuse or
negligence. To receive full value from the warranty,
operator must maintain mower as instructed in this
manual.
Some adjustments will need to be made periodically
to properly maintain your unit.
At least once a season, check to see if you should
make any of the adjustments described in this
Maintenance section.
• At least once a year, replace the spark plug,
clean or replace air filter element and check
blade for wear. A new spark plug and clean/
new air filter element assure proper air-fuel
mixture and help your engine run better and
last longer.
• Follow the maintenance schedule in this
manual.
Before Each Use
1. Check engine oil level.
2. Check for loose fasteners.

Ignition System

The engine is equipped with an electronic ignition
system. Only the spark plugs require maintenance.
For recommended spark plugs, see Technical Data.
1. Remove the ignition cable boot and clean
around the spark plug.
2. Remove the spark plug with a spark plug
socket wrench.
3. Check the spark plug. Replace the spark plug if
fouled, the electrodes are burned and if the
insulation is cracked or damaged. Clean the
spark plug with a steel brush if it is to be
reused.
4. Measure the electrode gap with a gapping
tool. The gap should be .030" (0.75 mm).
Adjust as necessary by bending the side
electrode.
5. Reinsert the spark plug, turning by hand to
avoid damaging the threads.
After the spark plug is seated, tighten it
using a spark plug wrench so that the
washer is compressed. A used spark plug
should be turned 1/8 of a turn from the
seated position. A new spark plug should be
turned 1/4 a turn from the seated position.
6. Replace the ignition cable.
MAINTENANCE
IMPORTANT INFORMATION
Fitting the wrong spark plug type can
damage the engine.
Inadequately tightened spark plugs can
cause overheating and damage the
engine. Tightening the spark plugs too
hard can damage the threads in the
cylinder head.
Measure the electrode gap
8011-054
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