Maintenance; Troubleshooting - MTD 138-320-000 Owner's Manual

MAINTENANCE
A
t WARNING i
>»♦♦♦♦♦♦♦«»
Disconnect ihe spark plug wire
and ground against the engine be¬
fore performing any repairs or main¬
tenance.
TROUBLE SHOOTING
Refer to page 21 of this manual for trouble shooting
information.
CRANKCASE OIL
Check the oil level in the crankcase before each use
of the machine and after every five hours of operation.
Oil level should be maintained as instructed in the
separate engine manual.
After the first five hours of operating a new engine, drain
the oil from the crankcase while engine is still hot and
refill crankcase with new oil; thereafter change the oil
every 25 hours of operation. Refer to the engine
manual.
AIR CLEANER
Under normal operating conditions, the air cleaner,
located on top of the carburetor, must be serviced after
every ten hours of use. Under extremely dusty
operating conditions, the air cleaner must be serviced
after every hour of operation. To service the air cleaner,
refer to the separate engine manual packed with your
unit.
CLEANING ENGINE AND BLADE HOUSING
Any fuel or oil spilled on the machine should be wiped
off promptly. Grass, leaves, and other dirt must not be
left to accumulate around the cooling fins of the engine
or on any part of the machine.
Clean the underside of the blade housing after each
mowing.
SPARK PLUG
The spark plug should be cleaned and the gap reset
once a season. Spark plug replacement is recommend¬
ed at the start of each mowing season; check engine
manual for correct plug type and gap specification.
CUTTING BLADE
A. Removal for Sharpening or Replacement
WARNING
Be sure to disconnect and ground
the spark plug wire and remove
ignition key before working on the
cutting blade to prevent accidental
engine starting. Protect hands by using
heavy gloves or a rag to grasp the
cutting blades.
1. Remove the large bolt and lock washer which holds
the blade and adapter to the blade spindle.
2. Remove the blade and adapter from the spindle.
3. If the blade or blade adapter needs replacing,
remove the two smali bolts, lock washers and nuts
which hold the blade to the adapter.
B. Sharpening
Remove the cutting blade by following the directions
of the preceding section.
When sharpening the blade, follow the original angle
of grind as a guide. It is
extremely important
that each
cutting edge receives an equal amount of grinding to
prevent an unbalanced blade. An unbalanced blade will
cause excessive vibration when rotating at high speeds,
may cause damage to the mower and could break,
causing personal injury.
The blade can be tested for balance by balancing it on
a round shaft screwdriver. Remove metal from the
heavy side until it balances evenly.
■^NOTE
It is recommended that the blade
always be removed from the adapter
for the best test of balance.
C. Reassembly
Before reassembling the blade and the blade adapter
to the unit, lubricate the spindle and the inner surface
of the blade adapter with light oil. Lubricating the bolt
holes, bolts and inner surface of the nuts with light oil
is also recommended. A 4 oz. plastic bottle of light oil
lubricant is available. Order part number 737-01 70j
Engine oil may also be used. 1
When replacing the blade, be certain the wide blade
is assembled on the right side of the deck. Be sure to
install the blades with the side of the blades marked
"Bottom" (or with part number) facing the ground when
the mower is in the operating position.
Blade Mounting Torque
3/8" Dia. Bolt 375 in. lb. min., 450 in. lb. max.
5/16" Dia. Bolt 150 in. lb. min., 250 in. lb. max.
To insure safe operation of your unit, ALL nuts and bolts
must be checked periodically for correct tightness.
FUEL FILTER
Your unit is equipped with a replaceable incline fuel
filter. Replace filter whenever contamination or
discoloration is noticed. Order replacement filter
through your engine authorized service dealer.
DRIVE BELT REMOVAL AND REPLACEMENT
A
t
WARNING
t
♦♦♦♦♦♦♦♦♦
Disconnect the spark plug wire and
ground it against the engine. Block
the wheels of the unit.
17