STIGA ST400 Engine Instruction Manual

• Your engine must be used with caution. For this purpose, warnings have been placed on the engine.
• Pictograms, intended to remind you of precautions for use.
• Their meaning is explained below.
• We also recommend that you carefully read the safety regulations reported in the relevant chapter of this booklet.

1. Read carefully the instructions contained in this manual and the instructions of the machine on which this engine is mounted. Learn to stop the engine quickly. the engine.
2. Never allow the engine to be used by persons who are not familiar with the instructions.
3. Never operate the engine with people, especially children, or animals nearby. I hate it.
4. Remember that the operator or user

PRELIMINARY OPERA TIONS

1. Do not wear loose clothing, laces, jewelry, or other objects that could get caught; tie back long hair and keep a safe distance when starting.
2. Turn off the engine and let it cool before removing the fuel cap.
3. WARNING: DANGER! Gasoline is highly flammable.
   1. Store fuel in appropriate containers;
   2. Top up the fuel, using a funnel, only outdoors, and do not smoke during this operation and whenever handling fuel;
   3. Top up before starting the engine; do not add fuel or  remove the fuel cap when the engine is running or hot;
   4. if fuel is spilled, do not start the engine, but move the machine away from the area where the fuel was spilled, and avoid creating any possibility of fire, until the fuel has evaporated and the vapors have dissipated.
   5. Always replace and tighten the fuel tank and container caps securely.
4. Replace any faulty silencers and the guard, if damaged.

C) DURING USE

1. Do not operate the engine in enclosed spaces where dangerous carbon monoxide fumes can accumulate.
2. Do not use starting fluids or other similar products.
3. Do not change the engine settings or overrev the engine.
4. Do not tilt the machine sideways to the point that fuel leaks from the engine fuel tank cap.
5. Do not touch the cylinder fins and muffler guard until the engine has cooled down sufficiently.
6. Stop the engine and disconnect the spark plug wire before checking, cleaning or working on the machine or
7. Do not run the engine without a spark plug.
8. Transport the machine with an empty tank.

E) EMISSIONS
The combustion process generates toxic substances such as carbon monoxide, nitrogen oxides and hydrocarbons.

• Controlling these substances is important because of their ability to react to photochemical smog, and therefore to direct exposure to sunlight.
• Carbon monoxide does not react the same way to sun exposure, but it is still considered toxic.
• Our machines are equipped with emission reduction systems for the above-mentioned substances.

COMPONENTS AND CONTROLS

COMPONENTS

1. Oil filler cap with dipstick
2. Oil drain plug
3. Air filter cover
4. Spark plug cap
5. Engine serial number

ACCELERATOR CONTROL

The accelerator control (usually a lever), mounted on the machine, is connected to the engine via a cable. Consult the machine’s instruction manual to identify the accelerator lever and its positions, normally marked by
symbols, corresponding to: lul
CHOKE to be used for starting cold.
FAST corresponding to the maximum regime; to be used during work.
SLOW corresponding to the regime minimum.

ENVIRONMENTAL CONDITIONS
The operation of a four-stroke internal combustion engine is influenced by:
a) Temperature:

• Operating at low temperatures may cause cold starting difficulties.
• When operating at very high temperatures, hot starting difficulties may occur due to fuel evaporation in the carburetor bowl or pump.
• In any case, the type of oil must be adapted to the temperatures of use.

• The maximum power of an internal combustion engine progressively decreases as the altitude above sea level increases.
• By significantly increasing the altitude, it is therefore necessary to reduce the load on the machine, avoiding particularly strenuous work.

FUEL
Good fuel quality is essential for proper engine operation.
Fuel must meet the following requirements:

• a) Use clean, fresh, unleaded gasoline with a minimum of 90 octane; b) Do not use fuel with a percentage of ethanol above 10%; c) Do not add oil; d) To protect the fuel system from resinous deposits, add a fuel stabilizer.

OIL
Always use good quality oils, choosing the grade based on the temperature of use.

• a) Use only high-quality cleansing oil. Higher than SF-SG.
• b) Select the SAE viscosity grade according to the following
  table: – from 5 to 35 oc  = SAE 30 -from -15 to +35 C = o low-30 (Multigrade)
• c) Using multigrade oil may result in higher consumption in hot weather, so check the level more frequently.
• d) Do not mix oils of different brands and characteristics.
• e) Using SAE 30 oil at temperatures below +50C may damage the engine due to inadequate lubrication.
• f) Do not top up above the ‘IMAX’ level (see 5.1.1 ); an excessive level may cause smoke from the exhaust;
• fouling of the spark plug or air filter, resulting in difficulty starting.

R FILTER
The effectiveness of the air filter is crucial in preventing debris and dust from being sucked into the engine, reducing its performance and lifespan.

• a) Keep the filter element free from debris and always in perfect working order (see 6.5).
• b) If necessary, replace the filter element with an original spare part; incompatible filter elements can compromise the efficiency and life of the engine.
• c) Never start the engine without the element. filter correctlv mountedRULES OF USE

BEFORE EACH USE
Before each use of the engine, it is a good idea to carry out a series of checks aimed at ensuring regular operation.

CHECKING the oil level
For the type of oil to use, follow the instructions given in the specific chapter (see 8.1).

• a) Place the machine on a level surface.
• b) Clean the area around the filler cap.
• c) Unscrew the cap
  • Clean the end of the dipstick level
  • and insert it by placing the cap on the filler neck, as illustrated, without screw it on.
• d) Remove the cap again with the dipstick and check the oil level, which must be between the two notches “MIN” and “MAX”.
• e) Top up, if necessary, with engine oil.  Same type, until reaching the “MAX” level, being careful not to spill oil outside the filling hole.
• f) Screw the cap (1) back on tightly and clean all parts of any trace of oil spilled.

Refueling
IMPORTANT: Avoid spilling fuel on plastic parts of the engine or machine to avoid damaging them, and immediately clean up any spilled fuel. Damage to plastic parts caused by fuel is not covered by the warranty.
The fuel characteristics are reported in the specific chapter (see 4.2 and 8.1).
Refueling must be done under engine power, cold, according to the instructions provided in the Manual of Machine Instructions.

Spark plug cap
Connect the cable cap

1. firmly to the spark plug
2. making sure that there are no traces of dirt inside the hood itself and on the spark plug terminal.

STARTING THE ENGINE (cold)
The engine must be started according to the methods indicated in the Instruction Manual of the machine, always taking care to disengage any device (if provided) capable of to generate the advancement of the machine or of stopping the engine.

• a) Move the accelerator lever to position «CHOKE».
• b) Turn on the ignition key as indicated in the machine’s instruction manual. After a few seconds, gradually bring the accelerator lever from the «CHOKE» position to the «FAST» or «SLOW» position.

STARTING THE ENGINE (hot)
Follow the entire procedure indicated for cold starting, with the accelerator in position «FAST».

USE DURING THE WORK
To optimize the performance and efficiency of the engine, it is necessary that it is used at maximum revs, moving the accelerator lever to «FAST» position.

STOPPING THE ENGINE AT THE END OF WORK

• a) Move the accelerator to the «SLOW» position.
• b) Let the engine idle for at least 15-20 seconds.
• c) Stop the engine as directed in the machine’s instruction manual.
• d) With the engine cold, disconnect the cap (1)  of the spark plug and remove the ignition key (if applicable).
• e) Remove any debris buildup from the engine and, in particular, from the silencer area of the exhaust to reduce the risk of fire

CLEANING AND STORAGE

• a) Do not use water jets or pressure washers for cleaning the external parts of the engine.
• b) Preferably use a compressed air gun (max 6 bar), avoiding debris and dust from penetrating the internal parts.
• c) Store the machine (and the engine) in a safe, dry place, sheltered from the elements and sufficiently ventilated.

PROLONGED INACTIVITY (over 30 days)
If a long period of non-use is expected of the engine (for example at the end of the season), it is necessary to implement some precautions to facilitate subsequent recommissioning.

• a) To prevent deposits from forming on its inside, empty the fuel tank
  unscrewing the cap (1) of the carburetor bowl, collecting all the fuel in a suitable container. At the end of the operation, remember to screw the cap (1) back on, tightening it tightly.
• b) Remove the spark plug and insert it into the spark plug hole about 3 cl of clean engine oil, then, holding the hole closed with a rag, briefly operate the starter motor to turn the engine over a few times and distribute the oil over the internal surface of the cylinder. Finally, reassemble the spark plug, without connecting the cable cap.

MAINTENANCE SCHEDULE
Follow the maintenance schedule indicated in the table, respecting the deadline that appears first.
It is the responsibility of the machine owner to perform the maintenance operations described in the table below more frequently under particularly severe working conditions or if there is debris in the air.

USE
Filters should be cleaned/ replaced more often if the machine works on very dusty ground.

MAINTENANCE
Attempting to tamper with the emissions control system may raise emissions above the legal limit. This includes the removal or alteration of parts such as the intake system, fuel system, and exhausts stem.

IGNITION REPLACEMENT
For the type of oil to use, follow the instructions given in the specific chapter (see 8.1).

 FILTER MAINTENANCE OF THE AIR

• a) Clean the area around the cover (1) of the filter.
• b) Remove the cover (1) by unscrewing the two knobs (2 – TRE0701-TRE0801 or by unhooking the tongue (2a – TRE0702).
• c) Remove the filter element (3a + 3b).
• d) Remove the pre-filter (3b) from the cartridge (3a).
• e) Tap the cartridge (3a) on a solid surface and blow with compressed air from the side inside to remove dust and debris.
• f) Wash the sponge pre-filter (3b) with water and detergent and let it air dry.

PLUG CHECK AND MAINTENANCE

• a) Remove the spark plug (1) with a wrench tube (2).
• b) Clean the electrodes (3) with a wire brush, removing any carbon deposits.
• c) Check the correctness of the seal with a feeler gauge (4). Distance between electrodes (0.6 – 0.8 mm).
• d) Refit the spark plug (1) and tighten it securely with a socket wrench (2). Replace the spark plug if the electrodes are burned or if the porcelain appears broken or cracked.

USAGE INSTRUCTION

TROUBLE SHOOT