31
Checking the Spark Plugs
1. Look at the center of the spark plugs (Fig. 33). 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.
2. If needed, clean the spark plug with a wire brush to
remove carbon deposits.
0.030 inch
(0.75 mm)
2
3
1
Figure 33
1.
Center electrode insulator
2.
Side electrode
3.
Air gap (not to scale)
Important
Always replace the spark plugs when it has
a black coating, worn electrodes, an oily film, or cracks.
3. Check the gap between the center and side electrodes
(Fig. 33). Bend the side electrode (Fig. 33) 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 16 ft-lb (22 N
m).
3. Connect the wires to the spark plugs (Fig. 32).
Cleaning the Cooling System
Clean the air intake screen from grass and debris before
each use.
Check and clean cooling fins and engine shrouds every
100 hours or yearly, which ever comes first.
1. Disengage the PTO and set 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, recoil starter and fan
housing.
4. Clean the debris and grass from the engine parts.
5. Install air intake screen, recoil starter and fan housing.
3
2
4
1
m–7450
5
Figure 34
1.
Air intake screen
2.
Fan housing
3.
Recoil starter
4.
Bolt
5.
Nut
Fuse Service
Service Interval/Specification
The electrical system is protected by a fuse. It requires no
maintenance. If the fuse blows check component or circuit
for malfunction or short. To replace fuse pull out on the
fuse to remove or replace it (Fig. 35).
m–5390
1
m–5391
Figure 35
1.
Fuse, 10 amp, blade type
