Cleaning The Cooling System; Spark Plug - Toro 74406 Operator's Manual

2. Place the air cleaner assembly onto the
air cleaner base and install the wing nut
(Figure 27).
3. Install the air cleaner cover and secure the
latches (Figure 27).

Cleaning the Cooling System

Clean the air intake screen from grass and debris
before each use.
Clean the cooling fins and engine shrouds every
300 hours or yearly, whichever comes first.
1. Disengage the blade control switch and move
the control levers to the neutral locked position
and apply the parking brake.
2. Stop the engine, remove the key, and wait for
all moving parts to stop before leaving the
operating position.
3. Remove the air intake screen, cylinder covers,
and fan housing.
4. Clean debris and grass from the parts.
5. Install the air intake screen, cylinder covers,
and fan housing.
Figure 30
1. Air intake screen
2. Fan housing

Spark Plug

Check the spark plug(s) after every 200 operating
hours. Make sure that the air gap between the
center and side electrodes is correct before
3. Cylinder cover
4. Cylinder cover
installing the spark plug. Use a spark plug wrench
for removing and installing the spark plug(s) and a
gapping tool/feeler gauge to check and adjust the
air gap. Install a new spark plug(s) if necessary.
Type: Champion RC12YC (or equivalent)
Air Gap: 0.030 inch (0.76 mm)
Removing the Spark Plug(s)
1. Disengage the blade control switch and move
the control levers to the neutral locked position
and apply the parking brake.
2. Stop the engine, remove the key, and wait for
all moving parts to stop before leaving the
operating position.
3. Pull the wire(s) off of the spark plug(s)
(Figure 31). Clean around the spark plug(s) to
prevent dirt from falling into the engine and
potentially causing damage.
4. Remove the spark plug(s) and metal washer.
Figure 31
1. Spark plug wire installed
Checking the Spark Plug
1. Look at the center of the spark plug(s)
(Figure 32). 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(s). Always replace the spark plug(s)
when it has a black coating, worn
electrodes, an oily film, or cracks.
2. Check the gap between the center and side
electrodes (Figure 32). Bend the side electrode
(Figure 32) if the gap is not correct.
27
2. Spark plug