Servicing The Spark Plug - Toro 74179 Operator's Manual

Servicing the Spark Plug

Check the spark plug(s) after every 100 operating hours.
Make sure that the air gap between the center and side
electrodes is correct before 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: NGK BPR5ES (or equivalent)
Air Gap: 0.030 in. (0.76 mm)
Removing the Spark Plug
1. Disengage the power take off (PTO), set the parking
brake, stop the engine, and remove the key.
2. Pull the wire(s) off of the spark plug(s) (Fig. 37). Clean
around the spark plug(s) to prevent dirt from falling into
the engine and potentially causing damage.
3. Remove the spark plug(s).
1
Figure 37
1. Spark plug wire installed
(s)
2
m–4294
2. Spark plug
32
Checking the Spark Plug
Clean or replace the spark plug and set the gap every 100
hours.
1. Look at the center of the spark plug(s) (Fig. 38). 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
Always replace the spark plug(s) when it
has a black coating, worn electrodes, an oily film, or
cracks.
2. Clean the electrode by scraping or with a wire brush to
remove carbon deposits and wetness.
3. Check the gap between the center and side electrodes
(Fig. 38). Bend the side electrode (Fig. 38) if the gap is
not correct.
2
1
Figure 38
1. Center electrode insulator
2. Side electrode
Installing the Spark Plug
1. Install the spark plug(s). Make sure that the air gap is
set correctly.
2. Tighten the spark plug(s) to 16 ft.-lb. (22 N m).
3. Push the wire(s) onto the spark plug(s) (Fig. 37).
3
0.030 in.
(0.76 mm)
m–3215
3. Air gap (not to scale)
(s)