Figure 22
3. Install a new air filter and the air filter cover.
Changing the Engine Oil
Service Interval: After the first 5 hours
Every 50 hours
Run the engine a few minutes before changing the oil
to warm it. Warm oil flows better and carries more
contaminants.
1. Perform the pre-maintenance procedures; refer to
Preparing for Maintenance.
2. If the grass bag is on the mower, remove it.
3. Drain the gasoline from the fuel tank; refer to
Emptying the Fuel Tank.
4. Remove the dipstick (Figure 6).
5. Remove the dipstick from oil fill tube and place
a drain pan next to the left side of the mower
(Figure 23).
Figure 23
6. After draining the oil, return the mower to its
operating position.
7. Slowly pour oil into the oil fill tube until the oil level
reaches the Full mark on the dipstick (Figure 6).
Do not overfill. (Max. fill: 0.59 l, type: SAE 30
detergent oil with an API service classification of SF,
SG, SH, SJ, SL, or higher.)
8. Install the dipstick securely.
9. Wipe up any spilled oil.
10. Dispose of the used oil properly at a local recycling
center.
Charging the Battery
Service Interval: Every 25 hours—Charge the battery
for 24 hours (model 20638 only).
Model 20638 only
Always use the charger in a sheltered area and charge the
battery at room temperature (22° C) whenever possible.
1. Connect the charger to the mower wire harness
located below the ignition key (Figure 24).
2. Plug the charger into a wall outlet.
Note: When the battery no longer holds a charge,
recycle or dispose of the lead-acid battery according
to local codes.
Replacing the Fuse
Model 20638 only
If the battery does not charge or the engine does not run
with the electric starter, the fuse may be blown. Replace
it with a 40-amp plug-in type fuse. Refer to Installing
the Fuse.
12
Figure 24