STIHL RM 248.3 / RM 253.3 Petrol Lawn Mower

Preface

STIHL is pleased that you have chosen their product. STIHL develops and manufactures its products with a focus on quality and user needs, ensuring high reliability even under extreme conditions. STIHL also stands for top quality in service, with specialized workshops offering competent advice and comprehensive technical support. The company is committed to environmental protection. These operating instructions are designed to help you use your STIHL product safely and ecologically for a long service life. Thank you for your trust.

IMPORTANT! READ AND KEEP THESE INSTRUCTIONS BEFORE USE.

Identifying Warning Notes in Text:

• DANGER: Indicates hazards that will result in severe injury or death. Specified measures can prevent severe injury or death.
• WARNING: Indicates hazards that could result in severe injury or death. Specified measures can prevent severe injury or death.
• NOTICE: Indicates hazards that could result in property damage. Specified measures can prevent property damage.

Symbols in Text: This symbol refers to a chapter in these operating instructions.

Table of Contents

A detailed table of contents is provided in the original document, listing sections such as:

• Preface
• Information regarding this Manual
• Table of Contents
• Safety Instructions
• Preparation for Operation
• Assembly
• Fueling
• User Adjustments
• Starting and Stopping the Engine
• Checking the Lawn Mower
• Working with the Lawn Mower
• After Use
• Transport
• Storage
• Cleaning
• Maintenance
• Repairs
• Troubleshooting
• Technical Data
• Spare Parts and Accessories
• Disposal
• Declarations of Conformity (EU, UKCA)
• Addresses

Safety Instructions

General Safety Warnings:

• Always read and understand the operating instructions and engine instructions before use.
• Ensure the lawn mower is used only for its intended purpose: mowing and mulching grass.
• Do not operate the mower if it is damaged or if fuel is leaking.
• Keep the fuel tank cap securely closed.
• Ensure the engine oil filler cap is closed.
• Keep the mower clean.
• Operate controls only when they are functioning correctly and have not been modified.
• If the mower is borrowed, provide the instructions to the new user.
• Users must be well-rested, physically, sensorially, and mentally fit to operate the mower.
• Users must be able to recognize and assess hazards.
• Users must be aware of their responsibility for accidents and damages.
• Users must be of legal age or trained under supervision.
• Users must be instructed by an authorized STIHL dealer or qualified person before first use.
• Do not operate under the influence of alcohol, medication, or drugs.

Protective Clothing and Equipment:

• Wear long, sturdy trousers.
• Use hearing protection (earmuffs).
• Wear a dust mask if dust is generated.
• Wear close-fitting clothing.
• Remove jewelry and scarves.
• Wear sturdy, closed-toe shoes with non-slip soles.
• Wear safety glasses that fit snugly.

Work Area and Environment:

• Keep bystanders, children, and animals away from the work area.
• Maintain distance from objects.
• Do not leave the mower unattended.
• Ensure children do not use the mower as a toy.
• Be aware of hot exhaust gases; keep away from flammable materials.
• Do not operate in wet conditions or on slopes exceeding 25° (46.6%).
• Avoid working near slopes, terraces, ditches, or embankments.
• Do not operate in areas with flammable or explosive atmospheres.
• Do not work during thunderstorms.
• Do not work in the rain.

Safe Operating Condition:

• The mower must not be damaged.
• No fuel or oil leaks.
• Fuel and oil caps must be closed.
• The mower must be clean.
• Controls must be functional and unmodified.
• Ensure correct configuration for grass collection, side discharge, or mulching.
• The blade must be correctly mounted, sharp, and balanced.
• Use only genuine STIHL parts and accessories.
• Ensure all spring-loaded mechanisms are undamaged and functional.
• The engine must stop when the clutch lever is released.

Blade Safety:

• Never touch the blade while it is rotating.
• If the blade is blocked by an object, stop the engine before removing the object.
• Wait for the blade to stop rotating before detaching the grass catcher or performing other maintenance.
• If the blade hits a hard object, sparks may be generated, potentially igniting flammable materials.

Fueling and Refueling:

• Use only unleaded, branded, fresh gasoline.
• Do not smoke while fueling.
• Refuel in a well-ventilated area, away from open flames or heat sources.
• Stop the engine and allow it to cool before refueling.
• If the fuel tank needs to be emptied, do this outdoors.
• Start the engine at least 3 meters away from the refueling point.
• Do not store the mower with fuel in the tank inside a building.
• Inhaling gasoline vapors can be toxic.
• Gasoline is highly flammable. Keep away from heat and fire.
• If gasoline spills on skin or eyes, wash immediately with plenty of water and soap or rinse eyes for at least 15 minutes and seek medical attention.

Transport and Storage:

• Always stop the engine and remove the spark plug wire before transport or storage.
• Secure the mower properly during transport to prevent it from tipping or moving.
• Allow the engine and muffler to cool down before handling.
• Use gloves when handling the mower.
• Transport the mower with two people if necessary.
• Store the mower in a dry, clean place, inaccessible to children.
• Ensure the mower is stable and cannot accidentally roll away.

Operation

Starting the Engine:

1. Position the lawn mower on a flat surface.
2. Press the clutch lever towards the handlebar and hold it.
3. Slowly pull the starter handle until resistance is felt.
4. Quickly pull the starter handle and let it return to its initial position until the engine starts.
5. If the engine does not start, refer to the engine operating instructions.

Stopping the Engine:

1. Position the lawn mower on a flat surface.
2. Release the clutch lever. The engine will stop.
3. Step away from the working position.

Adjusting the Handlebar: The handlebar can be folded down for transport or storage.

Adjusting Cutting Height:

• Stop the engine and ensure the blade is not rotating.
• Place the mower on a flat surface.
• Hold the mower handle and press the lever, then adjust the mower to the desired height.
• The current cutting height is indicated by a marker.
• Release the lever; the mower will lock into position.

Working with the Mower:

• Hold the handlebar firmly with both hands.
• Mow at a slow, controlled pace.
• Mow only in good visibility conditions.
• Take breaks if you feel tired.
• If working on slopes, mow perpendicular to the slope.
• Do not operate on slopes steeper than 25°.
• Be cautious when working near slopes, terraces, ditches, or embankments.
• Do not inhale exhaust gases. Ensure good ventilation.
• If you experience nausea, headache, vision or hearing disturbances, or dizziness, stop working and consult a doctor.
• The engine and blade stop within 3 seconds of releasing the clutch lever.

Emptying the Grass Catcher:

• The fill level indicator shows when the grass catcher is full.
• Stop the mower, detach the grass catcher, empty it, and reattach it.

Transporting the Mower:

• Stop the engine and remove the spark plug wire.
• Secure the mower during transport to prevent movement.
• Lift the mower using the transport handle and handlebar, preferably with two people.
• If transporting by vehicle, secure it to prevent tipping or shifting.

Storage:

• Stop the engine and let it cool.
• Remove the spark plug wire.
• Store the mower in a dry, clean place inaccessible to children.
• Ensure the mower is stable and cannot roll away.

Cleaning, Maintenance, and Repairs

Cleaning:

• Stop the engine and let it cool.
• Remove the spark plug wire.
• Clean the mower with a damp cloth.
• Use a brush to clean air vents.
• Clean the area around the blade and the blade itself with a stick, soft brush, or damp cloth.
• Do not use high-pressure cleaners or water jets, as they can damage the mower.

Maintenance:

• Refer to the engine manual for engine maintenance.
• Annual inspection by an authorized STIHL dealer is recommended for the mower.

Blade Maintenance:

• Stop the engine and remove the spark plug wire.
• Place the mower in a vertical position.
• Block the blade with a piece of wood.
• Unscrew and remove the blade.
• Use a new blade bolt for mounting.
• Apply threadlocker (Loctite 243) to the blade bolt thread.
• Mount the blade correctly, ensuring the raised edges fit into the recesses.
• Tighten the blade bolt to 60 Nm.
• Sharpening and balancing the blade requires experience; it is recommended to have this done by an authorized STIHL dealer.

Repairs:

• Users cannot repair the mower or blade themselves.
• If the mower or blade is damaged, do not use it and contact an authorized STIHL dealer.

Troubleshooting

Engine Will Not Start:

• Ensure the clutch lever is engaged.
• Check fuel level; refuel if empty.
• Check fuel line for blockages.
• Use fresh, unleaded, branded gasoline.
• Clean or replace the air filter.
• Ensure the spark plug wire is properly connected to the spark plug.
• Clean or replace the spark plug; check electrode gap.

Engine Starts Poorly or Loses Power:

• Adjust cutting height to a higher setting.
• Mow in lighter grass.
• Ensure the mower housing is not clogged.
• Adjust cutting height or reduce forward speed.
• Check fuel tank and carburetor for water or contamination; clean fuel line and carburetor.
• Clean or replace the air filter.

Engine Overheats:

• Ensure the oil level is adequate.
• Clean cooling fins.

Mower Vibrates Heavily:

• Blade is damaged.
• Blade is incorrectly mounted.
• Blade is dull or worn.

Uneven Cutting:

• Blade is dull or worn.
• Blade is incorrectly mounted.

Technical Data

STIHL RM 248.3 / RM 253.3 Lawn Mower:

• Engine Type: STIHL EVC 205
• Displacement: 127 cm³
• Power: 1.8 kW (2.5 HP) at 2800 rpm
• Rated Speed: 2800 rpm
• Fuel Tank Capacity: 0.8 L
• Weight: RM 248.3: 30 kg, RM 253.3: 31 kg
• Grass Catcher Capacity: RM 248.3: 52 L, RM 253.3: 55 L
• Cutting Width: RM 248.3: 46 cm, RM 253.3: 51 cm

Blade Specifications:

• Minimum Thickness (a): 1.6 mm
• Minimum Width (b): 55 mm
• Grinding Angle (c): 30°

Noise and Vibration Levels:

• RM 248.3:
• Sound Pressure Level (LpA): 82 dB(A)
• Guaranteed Sound Power Level (LwAd): 96 dB(A)
• Vibration Level (ahv) at Handlebar: 4.4 m/s²
• RM 253.3:
• Sound Pressure Level (LpA): 83 dB(A)
• Guaranteed Sound Power Level (LwAd): 97 dB(A)
• Vibration Level (ahv) at Handlebar: 4.4 m/s²

REACH: Information regarding compliance with the European REACH Regulation is available at www.stihl.com/reach.

Declarations of Conformity

EU Declaration of Conformity:

STIHL Tirol GmbH declares that the product (Type: Lawn Mower, Models: RM 248.3, RM 253.3) complies with relevant EU directives (2000/14/EC, 2006/42/EC, 2014/30/EU, 2011/65/EU) and standards (EN ISO 5395-1, EN ISO 5395-2, EN ISO 14982).

UKCA Declaration of Conformity:

STIHL Tirol GmbH declares that the product (Type: Lawn Mower, Models: RM 248.3, RM 253.3) complies with applicable UK regulations (Noise Emission in the Environment by Equipment for use Outdoors Regulations 2001, Supply of Machinery (Safety) Regulations 2008, Electromagnetic Compatibility Regulations 2016, Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment Regulations 2012) and standards (EN ISO 5395-1, EN ISO 5395-2, EN ISO 14982).

Addresses

For addresses of STIHL service centers and distributors, please visit www.stihl.com.