Hayter Mowers RZT420H manual Servicing the Spark Plug, Cleaning the Blower Housing

		Figure 37		Figure 38
1.	Oil filter	3.	Adapter	1. Spark plug and wire location
2.	Gasket

15.Slowly pour approximately 80% of the specified oil into the filler tube (Figure 34).

16.Install the oil fill cap/dipstick and push firmly into place (Figure 34).

17.Check the oil level (Figure 34); refer to Checking the Oil Level.

18.Slowly add additional oil to bring it to the full mark.

19.Install the oil fill cap/dipstick and push firmly into place (Figure 34).

Servicing the Spark Plug

Service Interval: Every 200 hours—Check spark plug

condition and gap.

Every 500 hours—Replace the spark plug.

The spark plug is RFI compliant. Equivalent alternate brand plugs can also be used. Spark plug replacement is recommended at 500 hours.

Type: Champion XC12YC (or equivalent)

Air Gap: 0.030 inch (0.76 mm)

Removing the Spark Plug

1.Disengage the blade control switch, move the motion controls outward to the park position, stop the engine, and remove the key.

2.Pull the wire off of the spark plug (Figure 38). Clean around the spark plug to prevent dirt from falling into the engine and potentially causing damage.

Note: Due to the deep recess around the spark plug, blowing out the cavity with compressed air is usually the most effective method for cleaning.

The spark plug is most accessible when the blower housing is removed for cleaning.

3.Remove the spark plug and metal washer.

Checking the Spark Plug

1.Look at the center of the spark plug (Figure 39). 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 39). Bend the side electrode (Figure 39) if the gap is not correct.

Figure 39

1. Center electrode insulator 3. Air gap (not to scale)

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 38).

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.

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