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1
m4294
Figure 40
1.
Spark-plug (2)
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
1. Look at the center of the spark plugs (Fig. 41). 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.
0.030 in.
(0.75 mm)
2
3
1
Figure 41
1.
Center electrode insulator
2.
Side electrode
3.
Air gap (not to scale)
Important
Never clean the spark plugs. Always replace
the spark plugs when it has a black coating, worn
electrodes, an oily film, or cracks.
2. Check the gap between the center and side electrodes
(Fig. 41). Bend the side electrode (Fig. 41) if the gap is
not correct.
Installing the Spark Plug
s
1. Install the spark plugs and the metal washer. Ensure that
the air gap is set correctly.
2. Tighten the spark plugs to 11 ft.-lb. (15 N.m).
3. Connect the wires to the spark plugs (Fig. 40).
Checking the Tire Pressure
Service Interval/Specification
Maintain the air pressure in the front and rear tires as
specified. Check the pressure at the valve stem after every
50 operating hours or monthly, whichever occurs first
(Fig. 42). Check the tires when they are cold to get the most
accurate pressure reading.
Pressure: 15 psi (103 kPa) rear tires
25–30 psi (172–207 kPa) caster tires
1
Figure 42
1.
Valve stem
Cleaning the Cooling System
Service Interval/Specification
Before each use, check and clean engine cooling system.
Remove any buildup of grass, dirt or other debris from the
cylinder and cylinder head cooling fins, air intake screen on
flywheel end, and carburetor-governor levers and linkage.
This will help insure adequate cooling and correct engine
speed and will reduce the possibility of overheating and
mechanical damage to the engine.
