MTD SX800 User manual

Engine
Owner’s Manual
Models
SX800
OHV700
OHV710
OHV800
OHV880
OHV910
Operating & Maintenance Instructions

The safety alert symbol ()is used to identify safety information about hazards that can
result in personal injury.
A signal word (WARNING,DANGER, or CAUTION) is used with the alert symbol to indicate the
likelihood and the potential severity of injury. In addition, a hazard symbol may be used to
represent the type of hazard.
WARNING indicates a hazard which, if not avoided, could result in death or serious
injury.
DANGER indicates a hazard which, if not avoided, will result in death or serious injury.
CAUTION indicates a hazard which, if not avoided, might result in minor or moderate
injury.
CAUTION, when used without the alert symbol, indicates a situation that could result in
damage to the engine.
CAUTION:You should carefully read and understand the operating instructions for the
equipment on which your engine is placed.
BEFORE OPERATING ENGINE
Read entire Operating & Maintenance Instructions
A
ND
the instructions for the equipment this engine powers.
Failure to follow instructions could result in serious injury
or death.
THE OPERATING & MAINTENANCE INSTRUCTIONS CONTAIN
SAFETY INFORMATION TO
Make you aware of hazards associated with engines
Inform you of the risk of injury associated with those hazards,
and
Tell
y
ou how to avoid or reduce the risk of in
j
ur
y
.
THE INTERNATIONAL SYMBOLS USED ON
THE ENGINE OR IN THIS MANUAL INCLUDE:

HAZARD SYMBOLS AND MEANINGS

CONTENTS
1
CONTENTS
1. ENGINE SAFETY ………………………………………………..…………………………2,3 & 4
2. COMPONENTS & CONTROL LOCATIONS …………...…….…………………………………5
3. ENGINE OIL ………………………………………………..…....………………………………6 & 7
4. FUEL …………………………………………………………….…………………………………… 7
5. STARTING ENGINE …………………………………………...………………………………7 & 8
6. MAINTENANCE …………………………………………….…..…………… 8, 9, 10, 11, 12 & 13
7. STORAGE & TRANSPORTING …………………………..……..…………………… 14, 15 & 16
8. TROUBLESHOOTING ………………………………………………………………………….....17
9. TECHNICAL & CONSUMER INFORMATION ………………….………………………………..18
10.WARRANTY ………………………………………………………………………………………...19

ENGINE SAFETY
2
1. ENGINE SAFETY
IMPORTANT SAFETY INFORMATION
Most accidents with engines can be prevented if you follow all instructions in this manual and
on the engine. Some of the most common hazards are discussed below, along with the best
way to protect yourself and others.
Owner Responsibilities
The engines are designed to give safe and dependable service if operated according to
instructions. Read and understand this owner’s manual before operating the engine. Failure
to do so could result in personal injury or equipment damage.
Know how to stop the engine quickly, and understand the operation of all controls. Never
permit anyone to operate the engine without proper instructions.
Do not allow children to operate the engine. Keep children and pets away from the area of
operation.
Fuel and its vapours are extremely flammable and
explosive.
Fire or explosion can cause severe burns or death.
WHEN ADDING FUEL
Turn engine OFF and let engine cool at least 2 minutes before removing fuel cap.
Fill fuel tank outdoors or in well-ventilated area.
Do not overfill fuel tank. Fill tank to approximately 25mm below top of neck to allow
for fuel expansion.
Keep fuel away from sparks, open flames, pilot lights, heat, and other ignition
sources.
Check fuel lines, tank, cap, and fittings frequently for cracks or leaks. Replace if
necessary.
WHEN STARTING ENGINE
Make sure spark plug, muffler, fuel cap and air cleaner are in place.
Do not crank engine with spark plug removed.
If fuel spills, wait until it evaporates before starting engine.
If engine floods, place throttle in RUN and crank until engine starts.
WHEN OPERATING EQUIPMENT
Do not tip engine or equipment at angle which causes fuel to spill.
Do not choke carburettor to stop engine.
WHEN TRANSPORTING EQUIPMENT
Transport with fuel tank EMPTY
WHEN STORING FUEL OR EQUIPMENT WITH FUEL IN TANK
Store away from furnaces, stoves, water heaters or other appliances that have pilot
light or other ignition source because they can ignite fuel vapours.
WARNING

ENGINE SAFETY
3
Starting engine creates sparking.
Sparking can ignite nearby flammable gases.
Explosion and fire could result.
If there is natural or LP gas leakage in area, do not start engine.
Do not use pressurized starting fluids because vapours are flammable.
Rapid retraction of starter cord (kickback) will pull hand and
arm toward engine faster than you can let go.
Broken bones, fractures, bruises or sprains could result.
When starting engine, pull cord slowly until resistance is felt, then pull rapidly.
Direct coupled equipment components such as, but not limited to, blades, impellors,
pulleys, sprockets, etc., must be securely attached.
Engines give off carbon monoxide, an odourless, colourless,
poison gas.
Breathing carbon monoxide can cause nausea, fainting or death.
Start and run engine outdoors.
Do not start or run engine in enclosed area, even if doors or windows are open.
Rotating parts can contact or entangle hands, feet, hair, clothing,
or accessories.
Traumatic amputation or severe laceration can result.
Operate equipment with guards in place.
Keep hands and feet away from rotating parts.
Tie up long hair and remove jewellery.
Do not wear loose-fitting clothing, dangling drawstrings or items that could become
caught.
WARNING
WARNING
WARNING
WARNING

ENGINE SAFETY
4
Running engines produce heat. Engine parts,
especially muffler, become extremely hot.
Severe thermal burns can occur on contact.
Combustible debris, such as leaves, grass, brush,
etc. can catch fire.
Allow muffler, engine cylinder and fins to cool before touching.
Remove accumulated combustibles from muffler area and cylinder area.
Unintentional sparking can result in fire or electric
shock.
Unintentional start-up can result in entanglement,
traumatic amputation, or laceration.
BEFORE PERFORMING ADJUSTMENTS OR REPAIRS
Disconnect spark plug wire and keep it away from spark plug.
Disconnect battery at negative terminal (only engines with electric start).
WHEN TESTING FOR SPARK
Use approved spark plug tester.
Do not check for spark with spark plug removed.
WARNING
WARNING

COMPONENTS & CONTROL LOCATIONS
5
2. COMPONENTS & CONTROL LOCATIONS
CARBURETTOR
MUFFLER
FUEL CAP
FUEL TANK
SPARK PLUG AIR CLEANER
STARTER GRIP
PRIMER BULB

ENGINE OIL
6
3. ENGINE OIL
ENGINE OIL RECOMMENDATIONS (WE RECOMMEND THE USE OF GENUINE ROVER OIL)
Oil is a major factor affecting performance and service life. Use 4-stroke automotive detergent
oil.
SAE 10W-30 is recommended for general use. Other viscosities shown in the chart may be used
when the average temperature in your area is within the recommended range.
SAE Viscosity Grades
AMBIENT TEMPERATURE
The SAE oil viscosity and service classification are in the API label on the oil container. We
recommend that you use API SERVICE Category SE or SF oil.
CAUTION:This engine is shipped without oil. Check oil level before starting engine. If
you start the engine without oil, the engine will be damaged beyond repair and will not be
covered under warranty.
Check the engine oil level with the engine stopped and in a level position.
Remove the oil filler cap/dipstick and wipe it clean.
Insert the oil filler cap/dipstick into the oil filler neck as shown, but do not screw it in, then
remove it to check the oil level.
If the oil level is near or below the lower limit mark on the dipstick, fill with the recommended
oil to the upper limit mark. Do not overfill.
Reinstall the oil filler cap/dipstick.
Engine oil capacity: 0.55L
OIL FILLER CAP/
DIPSTICK
UPPER
LOWER Low Rise
Oil Filler High Rise Oil Filler

FUEL/STARTING ENGINE
7
CAUTION:
Do not overfill. Overfilling with oil may cause:
Smoking, Hard starting, Spark plug fouling, or Oil saturation of air filter.
Used oil should be sent to special recycle bin for disposing.
4. FUEL
FUEL RECOMMENDATIONS
Use clean, fresh, regular unleaded fuel with a minimum of 85 octane.
These engines are certified to operate on unleaded fuel. Unleaded fuel produces fewer
engine and spark plug deposits and extends exhaust system life.
Never use stale or contaminated fuel or an oil/fuel mixture. Avoid getting dirt or water in the
fuel tank.
Occasionally you may hear a light ‘‘spark knock’’ or ‘‘pinging’’ (metallic rapping noise) while
operating under heavy loads. This is no cause for concern.
If spark knock or pinging occurs at a steady engine speed, under normal load, change
brands of fuel. If spark knock or pinging persists, see an authorized servicing dealer.
Fuel tank capacities:
OHV700, OHV710 : 1.0L
SX800, OHV800, OHV880 & OHV910: 1.2L
DANGER:Fuel and its vapours are extremely flammable and explosive.
5. STARTING ENGINE
5.1 Primer Equipped Engine (see location of Primer Bulb on page 5)
•Push Primer Bulb firmly 3 Times before starting.
FOR RESTARTINGA WARM ENGINE: Do not use the Primer Bulb when engine is warm.
5.2 Choke Equipped Engine
FOR STARTING A COLD ENGINE: Move the Throttle Control Lever to the choke/start
position.
Choke/Start Position Shown:
FOR RESTARTING A WARM ENGINE: Do not use the choke when the engine is warm.
Move the Control Lever slightly past the idle position.
5.3 Start Engine
Move the Blade Control Lever towards the handle bar(Refer to Mower Owners Manual).
Grasp rope handle. Pull slowly until resistance is felt, then pull rapidly to start engine and
avoid kickback.
If the choke was used to start the engine(Choke equipped engines only), move the throttle to
the run position as soon as the engine warms up enough to run smoothly without use of the
choke.
Do not use pressurized starting fluids.
Va
p
ours are flammable.
WARNIN
G

STARTING ENGINE/MAINTENANCE
8
CAUTION:Carefully check if there is enough oil before starting.
DANGER:Rapid retraction of starter cord (kickback) will pull hand and arm toward
engine faster than you can let go.
Rotating parts can contact or entangle hands, feet, hair, clothing, or accessories.
Running engines produce heat. Engine parts, especially muffler, become extremely hot.
Severe thermal burns can occur on contact.
5.4 Stopping Engine
Move the Throttle Control Lever to the Slow / Stop position and release the Blade Control
Lever.
6. MAINTENANCE
THE IMPORTANCE OF MAINTENANCE
Good maintenance is essential for safe, economical, and trouble-free operation. It will also help
reduce air pollution.
MAINTENANCE SAFETY
Regular maintenance will improve the performance and extend the life of the engine.
Improperly maintaining this engine, or failure to correct a problem before operation,
can cause a malfunction in which you can be seriously hurt or killed.
Always follow the inspection and maintenance recommendations and schedules in this
owner’s manual operating and maintenance instructions.
WARNING
Failure to properly follow maintenance instructions and precautions can cause you to
be seriously hurt or killed.
Always follow the procedures and precautions in the owner’s manual operating and
maintenance instructions.
WARNING

MAINTENANCE
9
Safety Precautions
Make sure the engine is off before you begin any maintenance or repairs. This will
eliminate several potential hazards:
Carbon monoxide poisoning from engine exhaust.
Be sure there is adequate ventilation whenever you operate the engine.
Burns from hot parts.
Let the engine and exhaust system cool before touching.
Injury from moving parts.
Do not run the engine unless instructed to do so.
Read the instructions before you begin, and make sure you have the tools and skills
required.
To reduce the possibility of fire or explosion, be careful when working around fuel. Use
only a non-flammable solvent, not fuel, to clean parts. Keep cigarettes, sparks and flames
away from all fuel-related parts.
To ensure the best quality and reliability, use only new, genuine parts for repair and replacement.

MAINTENANCE
10
6.1 MAINTENANCE SCHEDULE
Replace the paper element type only.
(1) Change engine oil every 25 hours when used under heavy load or in high ambient
temperatures.
(2) Clean more often under dusty conditions or when airborne debris is present. Replace air
cleaner parts if very dirty.
(3) These items should be serviced by your servicing dealer. Refer to manual for service
procedures.
Failure to follow this maintenance schedule could result in non-warrantable failures.
CAUTION: Used oil is a hazardous waste product. Dispose of used oil properly. Do not
discard with household waste. We suggest you take used oil in a sealed container to your local
recycling centre or service station for reclamation.
6.2 CHANGE ENGINE OIL
Drain the used oil while the engine is warm. Warm oil drains quickly and completely. Before
draining oil, drain fuel from tank by running engine until fuel tank is empty.
1. Place a suitable container below the engine to catch the used oil, and then remove the filler
cap/dipstick.
2. Tilt engine, keeping the air cleaner side up. Oil can be drained with spark plug side up if
necessary. Allow the used oil to drain completely.
3. With the engine in a level position, fill to the upper limit mark on the dipstick with the
recommended oil.
4. Reinstall the oil filler cap/dipstick securely.
Running the engine with a low oil level can cause engine damage.
REGULAR SERVICE PERIOD
Performed at every indicated
monthly or operating hour interval,
whichever comes first. Before
Each use
First
month or
5 Hrs.
Every 3
months
or 25 Hrs.
Every 6
months
or 50 Hrs.
Every
year or
100 Hrs.
ITEM
Engine oil Check level 
Change (1)
Air cleaner
Check 
Clean (2)
Replace 
Spark plug Check-Clean 
Replace 
Spark arrester
(optional parts) Clean 
Idle speed Check-Adjust (3)
Valve clearance Check-Adjust (3)
Combustion
chamber Clean After every 100 Hrs. (3)
Fuel line Check Every 2 years (Replace if necessary) (3)

MAINTENANCE
11
6.3 REFUELLING
With the engine stopped, remove the fuel tank cap and check the fuel level. Refill the tank if the
fuel level is low.
Refuel in a well-ventilated area before starting the engine. If the engine has been running, allow it
to cool. Refuel carefully to avoid spilling fuel. Fill tank to approximately 25mm below top of neck
to allow for fuel expansion. After refuelling, tighten the fuel tank cap securely.
Never refuel the engine inside a building where fuel fumes may reach flames or sparks. Keep
fuel away from appliance pilot lights, barbecues, electric appliances, power tools, etc.
Spilled fuel isn’t only a fire hazard, it causes environmental damage. Wipe up spills immediately.
CAUTION: Fuel can damage paint and plastic. Be careful not to spill fuel when filling
your fuel tank. Damage caused by spilled fuel is not covered under warranty.
6.4 AIR CLEANER
Remove the air cleaner cover and inspect the filter. Clean or replace dirty filter elements. Always
replace damaged filter elements.
CAUTION: A dirty air filter will restrict air flow to the carburettor, reducing engine
performance.
If you operate the engine in very dusty areas, clean the air filter more often than specified in the
MAINTENANCE SCHEDULE.

MAINTENANCE
12
INSPECTION
1. Press the latch tabs on the air cleaner cover, and remove the cover. Check the filter to
be sure it is clean and in good condition.
2. Reinstall the filter and air cleaner cover.
AIR CLEANER
COVER
AIR CLEANER
BODY LATCH TABS
FOAM FILTER
ELEMENT
AIR CLEANER
COVER
PAPER FILTER
ELEMENT
AIR CLEANER
BODY
LATCH TABS
FILTER, OUTER

MAINTENANCE
13
Cleaning Foam Filter Air Cleaner
1. Wash the element in a solution of water and liquid soap. Squeeze dry in a clean cloth.
2. Saturate element in engine oil and squeeze in a clean cloth to remove excess oil.
3. Wipe dirt from the air cleaner body. Be careful to prevent dirt from entering the air duct
that leads to the carburettor.
4. Fit element in air cleaner and replace cover making sure it is properly sealed.
Cleaning Paper Filter Air Cleaner
1. Tap the filter several times on a hard surface to remove dirt, or blow compressed air (not
exceeding 30 psi [207kPa, 2.1kg/cm²]) through the filter from the clean side that faces the
engine. Never try to brush off dirt. Brushing will force dirt into the fibres.
2. Tap the filter outer several times on a hard surface to remove dirt. If the filter outer is very
dirty, replace the filter outer.
3. Wipe dirt from the air cleaner body. Be careful to prevent dirt from entering the air duct that
leads to the carburettor.
CAUTION: Operating the engine without an air filter, or with a damaged air filter, will allow
dirt to enter the engine, causing rapid engine wear. This type of damage is not covered by the
Warranty.
6.5 SPARK PLUG SERVICE
Use Genuine Rover spark plugs.
CAUTION:
An incorrect spark plug can cause engine damage.
1. Disconnect the spark plug cap, and remove any dirt from
around the spark plug area.
2. Remove the spark plug with a spark plug wrench.
3. Inspect the spark plug. Replace it if the electrodes are worn, or if the insulator is cracked or
chipped.
4. Measure the spark plug electrode gap with a suitable gauge.
The gap should be 0.70 - 0.80 mm. Correct the gap, if necessary, by carefully
bending the side electrode.
5. Install the spark plug carefully, by hand, to avoid cross-threading.
6. After the spark plug seats, tighten with a spark plug wrench to compress the washer.
If reinstalling the used spark plug, tighten 1/8 - 1/4 turn after the spark plug seats.
If installing a new spark plug, tighten 1/2 turn after the spark plug seats.
CAUTION: A loose spark plug can overheat and damage the engine.
Over tightening the spark plug can damage the threads in the cylinder head.
7. Attach the spark plug cap.
0.70-0.80 mm

STORAGE & TRANSPORTING
14
7. STORAGE & TRANSPORTING
7.1 STORING YOUR ENGINE
7.1.1 Storage Preparation
Proper storage preparation is essential for keeping your engine trouble free and looking good.
The following steps will help to keep rust and corrosion from impairing your engine’s function and
appearance, and will make the engine easier to start after storage.
7.1.2 Cleaning
If the engine has been running, allow it to cool for at least half an hour before cleaning. Clean all
exterior surfaces, touch up any damaged paint, and coat other areas that may rust with a light
film of oil.
CAUTION: Using a garden hose or pressure washing equipment can force water into
the air cleaner or muffler opening. Water in the air cleaner will soak the air filter, and water that
passes through the air filter or muffler can enter the cylinder, causing damage.
Water contacting a hot engine can cause damage. If the engine has been running, allow it to cool
for at least half an hour before washing.
7.1.3 Fuel
Fuel will oxidize and deteriorate in storage. Old fuel will cause hard starting, and it leaves gum
deposits that clog the fuel system. If the fuel in your engine deteriorates during storage, you may
need to have the carburettor and other fuel system components serviced or replaced.
The length of time that fuel can be left in your fuel tank and carburettor without causing functional
problems will vary with such factors as fuel blend, your storage temperatures, and whether the
fuel tank is partially or completely filled. The air in a partially filled fuel tank promotes fuel
deterioration. Very warm storage/temperatures accelerate fuel deterioration. Fuel deterioration
problems may occur within a few months, or even less if the fuel was not fresh when you filled
the fuel tank.
The Warranty does not cover fuel system damage or engine performance problems resulting
from neglected storage preparation.
You can extend fuel storage life by adding a fuel stabiliser that is formulated for that purpose, or
you can avoid fuel deterioration problems by draining the fuel tank and carburettor.
Adding a Fuel Stabiliser to Extended Fuel Storage Life
When adding a fuel stabiliser, fill the fuel tank with fresh fuel. If only partially filled, air in the tank
will promote fuel deterioration during storage. If you keep a container of fuel for refuelling, be
sure that it contains only fresh fuel.
1. Add fuel stabiliser following the manufacturer’s instructions.
2. After adding a fuel stabiliser, run the engine outdoors for 10 minutes to be sure that treated
fuel has replaced the untreated fuel in the carburettor.
3. Stop the engine.

STORAGE & TRANSPORTING
15
SEALING WASHER
Draining the Fuel Tank and Carburettor
1. Place an approved fuel container below the carburettor, and
use a funnel to avoid spilling fuel.
2. Remove the carburettor drain bolt
and sealing washer.
3. After all the fuel has drained into the
container, reinstall the drain bolt and
sealing washer. Tighten them
securely.
7.1.4 Storage Precautions
1. Change the engine oil.
2. Remove the spark plug.
3. Pour a tablespoon (5-10 cc) of clean engine oil into the cylinder.
4. Pull the starter rope several times to distribute the oil in the cylinder.
5. Reinstall the spark plug.
6. Pull the starter rope slowly until resistance is felt. This will close the valves so moisture
cannot enter the engine cylinder. Return the starter rope gently.
If your engine will be stored with fuel in the fuel tank and carburettor, it is important to reduce
the hazard of fuel vapour ignition. Select a well-ventilated storage area away from any
appliance that operates with a flame, such as a furnace, water heater, or clothes dryer. Also
avoid any area with a spark-producing electric motor, or where power tools are operated.
If possible, avoid storage areas with high humidity, because that promotes rust and corrosion.
Position the equipment so the engine is level. Tilting can cause fuel or oil leakage.
7. With the engine and exhaust system cool, cover the engine to keep out dust. A hot engine
and exhaust system can ignite or melt some materials. Do not use sheet plastic as a dust
cover. A non-porous cover will trap moisture around the engine, promoting rust and corrosion.
If equipped with a battery for an electric starter, recharge the battery once a month while the
engine is in storage. This will help to extend the service life of the battery.
CARBURETTOR
FLOAT BOWL
DRAIN BOLT

STORAGE & TRANSPORTING
16
7.2 REMOVAL FROM STORAGE
Check your engine as described in the page 6 and 7.
If the fuel was drained during storage preparation, fill the tank with fresh fuel. If you keep a
container of fuel for refuelling, be sure that it contains only fresh fuel. Fuel oxidizes and
deteriorates over time, causing hard starting.
If the cylinders were coated with oil during storage preparation, the engine may smoke briefly at
start-up. This is normal.
7.3 TRANSPORTING
If the engine has been running, allow it to cool for at least half an hour before loading the
engine-powered equipment on the transport vehicle. A hot engine and exhaust system can burn
you and can ignite some materials.
Keep the engine level when transporting to reduce the possibility of fuel leakage.

TROUBLESHOOTING
17
8. TROUBLESHOOTING
ENGINE WILL NOT
START Possible Cause Correction
1. Choke
Equipped
Engine
Throttle Lever in wrong
position Move Throttle Lever to the
choke/start position unless
engine is warm. (page 7)
2. Primer
Equipped
Engine Incorrect use of Primer Bulb Push Primer Bulb firmly 3
times. (page 7)
3. Check fuel
Out of fuel Refuel (page 11)
Bad fuel; engine stored
without treating or draining
fuel, or refuelled with bad fuel
Drain fuel tank and
carburettor. Refuel with fresh
fuel. (page 15)
4. Remove and
inspect spark
plug
Spark plug faulty, fouled, or
improperly gapped Gap, or replace spark plug. (page 13)
Spark plug wet with fuel
(flooded engine)
Dry and reinstall spark plug.
Start engine with control lever
in RUN position
5. Take engine to
an authorised
servicing
dealer
Fuel filter clogged, carburettor
malfunction, ignition
malfunction, valve stuck, etc
Replace or repair faulty
components as necessary
ENGINE LACKS
POWER Possible Cause Correction
1. Check air filter Filter element(s) clogged Clean or replace filter
element(s). (page 11,12,13)
2. Check fuel
Out of fuel Refuel (page 11)
Bad fuel; engine stored
without treating or draining
fuel, or refuelled with bad fuel
Drain fuel tank and
carburettor. Refuel with fresh
fuel. (page 15)
3. Take engine to
an authorized
servicing dealer
Fuel filter clogged, carburettor
malfunction, ignition
malfunction, valve stuck, etc
Replace or repair faulty
components as necessary
ENGINE
OPERATES
ERRATICALLY Possible Cause Correction
1. Check spark plug Spark plug is defective Install new, correctly gapped
plug
Spark plug gap is incorrect Set gap (page 13)
2. Check air cleaner Air cleaner element is dirty Clean air cleaner element
. (page 11,12,13)