Troy-Bilt 31/2 HP - Manual (Page 21)

MAINTENANCE
Changing the Engine Oii
After the very first five hours that you operate your
new mower, change the engine oil. Thereafter, change
the engine oii every twenty-five hours of operation. If
you operate your mower in very dusty or dirty condi­
tions, change the engine oil even more frequently.
Use the following instructions when changing the
engine oil:
1. Run the mower engine until it is warm. Then SHUT
THE ENGINE OFF.
A CAUTION
Before changing the engine oii, shut the engine
off, disconnect the spark plug wire and prevent it
from touching the spark plug. For electric start
models, also remove the Engine Ignition key from
the keyswitch.
Failure to do this could result in personal injury
or property damage.
2. Place a drain pan with a minimum capacity of 2
quarts beneath the engine’s drain plug.
3. Use a pair of pliers to firmly grip the engine oil
drain tube as shown in Photo 5-3. This prevents the
drain tube from accidentally being unscrewed from
the base of the engine when you remove the drain
plug in the next step.
4. Use a 13/16-inch wrench (or a large adjustable
wrench) to unscrew the drain plug from the drain
tube. See Photo 5-3.
Photo 5-3: Draining the engine oil.
5. Allow all of the old oil to flow out of the engine.
6 . Again grip the drain tube with the pliers and reinstall
the drain plug on the oil drain tube. Very securely
tighten the drain plug.
7. Refill the engine with fresh oil. See “Checking the
Oil Level and Adding Oil to the Engine” on Page 18 for
specific instructions.
Air Cleaner Maintenance
The engine on your mower uses one of two types
of air filters. The 3 V 2 -horsepower engine has a single
element oil foam air cleaner. The 4-horsepower engine
has a dual element air cleaner (a replaceable paper
cartridge with an oiled foam pre-cleaner).
Before each use, always make sure that the air
cleaner is securely attached to the engine. A loose or
ill-fitting air cleaner assembly could allow dust or
dirt into the engine. This could shorten the life of
the engine.
Every 25 hours of engine operation (more frequently
if operating the mower in a very dusty or dirty envi­
ronment) clean and inspect the engine’s air cleaner
element(s).
To service the 3 V 2 -horsepower engine air cleaner:
1. Clean any excess dirt, dust, or chaff off the air
cleaner.
2. Remove the screw that secures the air cleaner
assembly to the engine. Lift the air cleaner assembly
up, off the engine.
3. Separate the body halves of the air cleaner assem­
bly and remove the foam element.
4. Clean this foam element as follows:
a. Thoroughly wash the element in a solution of
liquid detergent and water.
b. Wrap the element in a clean towel and squeeze
it dry.
c. Apply clean engine oil to the ends and sides of
the foam element. Knead the foam element to
evenly distribute the oil.
d. Squeeze any excess oil out of the foam element.
5. Thoroughly clean both halves of the air cleaner
body.
6 . Reinstall the foam element in the bottom half of the
body.
7. Place the air cleaner’s cup into the foam element
as shown in Figure 5-4.
8 . Place the top half of the body onto the bottom half.
Insert the screw into the top half of the air cleaner
and reinstall the air cleaner assembly onto the engine.
Figure 5-4: The 3 %-hor^power engine’s air cleaner as^nbly:
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