Installing The Spark Plugs; Checking The Spark Plugs - Toro 74410 Operator's Manual

Figure 36
1. Spark-plug wire/spark plug
4. Clean around the spark plugs to prevent dirt from
falling into the engine and potentially causing
damage.
5. Remove the spark plugs and the metal washers.

Checking the Spark Plugs

Service Interval: Every 100 hours
1. Look at the center of the spark plugs (Figure 37).
If you see light brown or gray on the insulator, the
engine is operating properly. A black coating on the
insulator usually means that the air cleaner is dirty.
2. If needed, clean the spark plug with a wire brush to
remove carbon deposits.
Figure 37
1. Center electrode insulator
2. Side electrode
Important: Always replace the spark plugs
when it has a black coating, worn electrodes,
an oily film, or cracks.
3. Check the gap between the center and side electrodes
(Figure 37). Bend the side electrode (Figure 37) if
the gap is not correct.
3. Air gap (not to scale)

Installing the Spark Plugs

1. Install the spark plugs and the metal washer. Ensure
that the air gap is set correctly.
2. Tighten the spark plugs to 16 ft-lb (22 N⋅m).
3. Connect the wires to the spark plugs (Figure 37).
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