MTD Series 790 Operator's Manual page 20

6.
7.
8.
9.
Pinch the tabs on the oil drain valve, then pull outward to
begin draining oil. SeeFig 6-2.
After the oil has finished draining, push the end of the oil
drain valve back in, until the tabs click into place. Re-cap
the end of the oil drain valve to keep debris from entering
the drain port.
Replace the oil filter as instructed in the separate engine
Owner's Manual.
Refill the engine with new oil. Refer to the engine Owner's
Manual for information regarding the proper volume and
weight of engine oil.
Air Cleaner
Service the pre-cleaner, if so equipped, and cartridge/air cleaner
element as instructed in the Engine Operator/Owner Manual
packed with your unit.
SparkPlug
The spark plug should be cleaned and the gap reset once a
season. Spark plug replacement is recommended at the start
of each mowing season. Refer to the Engine Operator/Owner
Manual for correct plug type and gap specifications.
Lubrication
_ ARNING! Before lubricating, repairing, or
inspecting, always disengage PTO, move shift lever
into neutral position, set parking brake, stop engine
and remove key to prevent unintended starting.
Engine
Lubricate the engine with motor oil as instructed in the Engine
Owner Manual packed with your unit.
Pivot Points & Linkage
Lubricate all the pivot points on the drive system, parking brake
and lift linkage at least once a season with light oil.
RearWheels
The rear wheels should be removed from the axles once a
season. Lubricate the axles and the rims well with an all-purpose
grease before re-installing them.
Front Axles
Each end of the tractor's front pivot bar may be equipped with a
grease fitting. Lubricate with a grease gun after every 25 hours of
tractor operation.
Battery
The battery is sealed and is maintenance-free. Acid levels cannot
be checked.
Always keep the battery cables and terminals clean and
free of corrosive build-up.
After cleaning the battery and terminals, apply a light coat
of petroleum jelly or grease to both terminals.
Always keep the rubber boot positioned over the positive
terminal to prevent shorting.
IMPORTANT:
If removing the battery for any reason,
disconnect the NEGATIVE(Black) wire from it's terminal first,
followed by the POSITIVE(Red) wire. When re-installing the
battery, always connect the POSITIVE(Red) wire its terminal
first, followed by the NEGATIVE(Black) wire. Be certain that the
wires are connected to the correct terminals; reversing them
could change the polarity and result in damage to your engine's
alternating system.
Charging
IMPORTANT:
When charging your tractor's battery, use only a
charger designed for 12V lead-acid batteries. Read your battery
charger's Owner's Manual prior to charging your tractor's battery.
Always follow its instructions and heed its warnings.
If your tractor has not been put into use for an extended period
of time, charge the battery as follows:
Set your battery charger to deliver a maximum of 10
amperes. If your battery charger is automatic, charge
the battery until the charger indicates that charging is
complete.
NOTE: If the charger is not automatic, charge for no fewer than
eight hours.
_ WARNING! Batteries give off an explosive gas
while charging. Charge battery in a well ventilated
area and keep away from an open flame or pilot
light as on a water heater, space heater, furnace,
clothes dryer or other gas appliances.
Jump Starting
i_ii WARNING! When removing or installing the
battery, follow these instructions to prevent the
screwdriver from shorting against the frame.
IMPORTANT: Never jump your tractor's dead battery with the
battery of a running vehicle.
I. Connect end of one jumper cable to the positive terminal
of the good battery, then the other end to the positive
terminal of the dead battery.
2. Connect the other jumper cable to the negative terminal
of the good battery, then to the frame of the unit with the
dead battery.
3. Start the tractor as instructed in the Operation section.
_I_lll ARNING! Failure to use this procedure could
cause sparking, and the gas in either battery could
explode.
CleaningBattery
Clean the battery by removing it from the tractor and washing
with a baking soda and water solution. If necessary, scrape the
battery terminals with a wire brush to remove deposits. Coat
terminals and exposed wiring with grease or petroleum jelly to
prevent corrosion.
Battery Failures
Some common causes for battery failure are:
Incorrect initial activation
Overcharging
SECTION 6-- MAINTENANCE
& ADJUSTMENTS