Cleaning The Blower Housing - Toro 74389 Operator's Manual

1. Spark plug and wire location
Checking the Spark Plug
1. Look at the center of the spark plug (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 the air cleaner is dirty.
Important: Never clean the spark plug. Always
replace the spark plug when it has a black coating,
worn electrodes, an oily film, or cracks.
2. Check the gap between the center and side electrodes
(Figure 37). Bend the side electrode (Figure 37) if the
gap is not correct.
1. Center electrode insulator
2. Side electrode
Installing the Spark Plug
1. Install the spark plug. Make sure that the air gap is set
correctly.
2. Tighten the spark plug to 30 ft-lb (41 N-m).
3. Push the wire onto the spark plug (Figure 36).
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G014537
Figure 36
Figure 37
3. Air gap (not to scale)

Cleaning the Blower Housing

To ensure proper cooling, make sure the grass screen, cooling
fins, and other external surfaces of the engine are kept clean
at all times.
Annually or every 100 hours of operation (more often under
extremely dusty, dirty conditions), remove the blower housing
and any other cooling shrouds. Clean the cooling fins and
external surfaces as necessary. Make sure the cooling shrouds
are reinstalled. Torque the blower housing screws to 5.5 ft-lb
(7.5 N-m).
Important: Operating the engine with a blocked grass
screen, dirty or plugged cooling fins, and/or cooling
shrouds removed, will cause engine damage due to
overheating.
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