MTD 839 Series Lawn Mower User Manual


 
10
5
Maintaining
Your Lawn
Mower
WARNING
Always stop engine,
disconnect spark plug,
and ground against
engine before cleaning,
lubricating or doing any
kind of maintenance on
your machine.
IMPORTANT: Do not
use a pressure washer
or garden hose to clean
your unit. These may
cause damage to electric
components, spindles,
pulleys, bearings, or the
engine. The use of water
will result in shortened life
and reduce serviceability.
Lubrication
1. Lubricate the pivot points on the blade control handle
at least once a season with light oil. The blade
control must operate freely in both directions. See
Figure 5-1.
2. If your mower is equipped with ball bearing wheels,
lubricate at least once a season with a light oil, all
other types require no lubrication. However, if the
wheels are removed for any reason, lubricate the
surface of the axle bolt and the inner surface of the
wheel with light automotive oil.
3. Lubricate the torsion spring and pivot point periodi-
cally with light oil to prevent rust. See Figure 5-1.
4. The transmission is pre-lubricated and sealed at the
factory and does not require lubrication.
5. Follow the accompanying engine manual for lubrica-
tion schedule and instruction.
Engine
1. Refer to the separate engine manual for engine
maintenance instructions.
2. Maintain engine oil as instructed in the separate
engine manual packed with your unit. Read and follow
instructions carefully.
3. Under normal conditions service air cleaner as
instructed in the separate engine manual packed with
your unit. Clean every few hours under extremely
dusty conditions. Poor engine performance and
flooding usually indicates that the air cleaner should
be serviced.
4. The spark plug should be cleaned and the gap reset
once a season. Spark plug replacement is recom-
mended at the start of each mowing season; check
engine manual for correct plug type and gap specifica-
tions.
NOTE: This spark ignition system meets all require-
ments of the Canadian Interference-Causing Equipment
Regulations.
5. Clean the engine regularly with a cloth or brush.
Keep the cooling system (blower housing area) clean
to permit proper air circulation which is essential to
engine performance and life. Be certain to remove all
grass, dirt and combustible debris from muffler area.
Deck
The underside of the mower deck should be cleaned after
each use to prevent a buildup of grass clippings, leaves,
dirt or other matter. If this debris is allowed to accumulate,
it will invite rust and corrosion, and may prevent proper
mulching.
The deck may be cleaned by tilting the mower and scrap-
ing clean with a suitable tool (make certain the spark plug
wire is disconnected).
Rear Flap Replacement
The rear flap is attached to the back of the mower deck,
and is designed to minimize the possibility that objects
will be thrown from the rear of the mower toward the
operator. If the rear flap becomes damaged, replace as
follows.
1. To remove the old rear flap, lift rear door, and press
flap in on either side to remove from hole. See Figure
5-2.
2. Remove flap from opposite hole and replace with new
flap following these steps in reverse order.
Blade Care
Periodically inspect the blade adapter for cracks,
especially if you strike a foreign object. Replace when
necessary. Follow the steps below for blade service:
1. Remove the bolt and the blade bell support which
hold the blade and the blade adapter to the engine
crankshaft. See Figure 5-3.
2. Remove blade and adapter from the crankshaft.
Figure 5-1
Figure 5-2