Stihl FR 235 User Manual (English)

Questions and Answers:

R
richardmontgomeryAug 6, 2025
Why Stihl FR 235 Trimmer engine does not start?
- J
  Jacqueline AcostaAug 6, 2025
  There are several reasons why your Stihl Trimmer engine might fail to start. It could be due to insufficient fuel in the tank, in which case you should prepare a fuel mix and refuel the trimmer. Alternatively, the engine might be flooded, requiring you to clear the combustion chamber. If the carburetor is too hot, allow the trimmer to cool down and depress the manual fuel pump bulb at least ten times before starting. Lastly, the carburetor might be iced up, so allow the trimmer to warm up to +10°C.
S
Savannah GriffinAug 15, 2025
What to do if Stihl FR 235 Trimmer cutting attachment rotates when engine is idling?
- T
  terri47Aug 15, 2025
  If the cutting attachment rotates when the engine is idling, turn the idle speed screw (LA) counterclockwise until the cutting attachment stops rotating. Alternatively, turn the idle speed screw (LA) one full turn counterclockwise.
J
josephjohnsonAug 26, 2025
How to fix erratic idling behavior or poor acceleration on a Stihl Trimmer?
- S
  Scott OlsonAug 26, 2025
  To fix erratic idling behavior or poor acceleration, turn the low speed screw (L) clockwise or counterclockwise until the engine runs and accelerates smoothly.

Stihl FR 235 Specifications

General

Engine Type	2-stroke
Shaft Type	Straight
Handle Type	Loop handle
Sound Power Level	107 dB(A)
Displacement	27.2 cc
Line Diameter	2.4 mm
Starter	Rewind starter

Summary

Guide to Using this Manual

Applicable Documentation

Lists supporting documents and local safety regulations to consult.

Symbols used with warnings in the text

Explains the meaning of warning symbols (WARNING, NOTICE) used in the manual.

Overview

Trimmer

Identifies and describes the various components of the STIHL FR 235 trimmer.

Deflectors and Cutting Attachments

Illustrates examples of deflectors and cutting attachments and their approved combinations.

Safety Precautions

Warning Signs

Explains warning signs and symbols found on the trimmer and its components.

Universal Deflector and Skirt

Details warning signs specific to the universal deflector and skirt.

Intended Use

Specifies the approved applications and limitations for the STIHL FR 235 backpack trimmer.

The Operator

Outlines user requirements, responsibilities, and essential safety information for the operator.

Clothing and equipment

Details necessary personal protective equipment (PPE) and clothing for safe operation.

Working Area and Surroundings

Covers safety requirements for the working environment, including bystanders and distances.

Safe Condition

Lists essential points to ensure the brushcutter is in a safe operating condition.

Deflector

Specifies safe condition requirements for the deflector.

Mowing Head

Lists points to ensure the mowing head is in a safe condition.

Metal cutting attachment

Details safe condition requirements for metal cutting attachments.

Fuel Mixture and Refueling

Provides essential safety warnings and instructions for mixing fuel and refueling.

Working

Offers guidance and warnings for safe operation of the trimmer.

Reactive forces

Explains kickback risks and how to prevent them during operation.

Transporting

Provides safety instructions for transporting the trimmer.

Storing

Guidelines for safely storing the trimmer, especially for long periods.

Cleaning, Maintenance and Repair

Outlines procedures and safety for cleaning, maintenance, and repair.

Preparing Trimmer for Operation

Lists steps required to prepare the trimmer before starting work.

Assembling the Trimmer

Assembling the Carrying System

Step-by-step guide to assembling the carrying system.

Mounting the Powerhead

Instructions for attaching the powerhead to the carrying system.

Mounting the Drive Tube

Details how to connect the drive tube to the powerhead.

Mounting Loop Handle with Barrier Bar

Guide for attaching the loop handle and barrier bar assembly.

Mounting and Removing the Deflector

Instructions for mounting and removing the deflector.

Mounting and Removing the Mowing Head

Instructions for mounting and removing the mowing head.

Removing the Mowing Head

Steps for safely removing the mowing head from the trimmer.

Removing and Installing Metal Cutting Attachment

Procedures for mounting and removing metal cutting attachments.

Adjusting Trimmer for User

Fitting and Adjusting the Carrying System

Guide on how to properly fit and adjust the carrying system for user comfort.

Removing the Carrying System

Instructions for safely removing the carrying system from the user.

Mixing Fuel and Refueling the Brushcutter

Mixing Fuel

Detailed instructions on how to correctly mix fuel for the trimmer.

Fueling the Trimmer

Steps for safely fueling the trimmer's fuel tank.

Starting and Stopping the Engine

Selecting the correct starting procedure

Guidance on choosing the appropriate starting procedure based on engine conditions.

Preparing Engine for Start

Steps to prepare the engine for starting, including manual fuel pump use.

Starting the Engine

Detailed procedure for starting the trimmer engine.

Stopping the Engine

Instructions on how to safely stop the trimmer engine.

Testing the Trimmer

Checking the Controls

Procedures to test the functionality of the trimmer's controls.

Operating the Trimmer

Adjusting Carburetor for Operation at High Altitude

Instructions for adjusting the carburetor for optimal performance at high altitudes.

Holding and Controlling the Trimmer

Guidance on proper grip and control techniques for operating the trimmer.

Mowing

Describes the mowing technique and how cutting height is determined.

After Finishing Work

When Work is Finished

Steps to take after completing work, including cleaning and cooling.

Transporting

Transporting the brushcutter

Procedures for safely transporting the brushcutter, including using guards.

Storing

Storing the Trimmer

Guidelines for safely storing the trimmer, especially for long periods.

Cleaning

Cleaning the Trimmer

Instructions for cleaning the main body of the trimmer.

Cleaning the Deflector and Cutting Attachment

Steps for cleaning the deflector and cutting attachment.

Maintenance

Maintenance Intervals

Specifies recommended maintenance intervals for the trimmer.

Lubricating and Turning Around the Flexible Shaft

Guide for lubricating and servicing the flexible shaft.

Lubricating the Gearbox

Instructions for lubricating the gearbox of the trimmer.

Adjusting the Throttle Cable

Steps for adjusting the throttle cable for proper engine response.

Sharpening and Balancing a Metal Cutting Attachment

Advice on sharpening and balancing metal cutting attachments.

Repairing

Repairing the Trimmer and Cutting Attachment

States that repairs are not user-serviceable and directs to dealer.

Troubleshooting Trimmer

Common problems and their solutions for the trimmer.

Replacing the Air Filter

Step-by-step guide for replacing the air filter.

Specifications

STIHL FR 235 Trimmer

Lists the technical specifications for the STIHL FR 235 Trimmer.

Sound Values and Vibration Values

Provides sound and vibration data for the trimmer.

REACH

Information regarding the REACH regulation.

Exhaust Emissions

Details on exhaust emissions and EU type approval.

Combinations of Cutting Attachments and Deflectors

Table showing compatible cutting attachments and deflector combinations.

Spare Parts and Accessories

Spare parts and accessories

Information and recommendations regarding genuine STIHL spare parts and accessories.

Disposal

Disposing of Trimmer

Guidance on proper disposal of the trimmer and its components.

EC Declaration of Conformity

STIHL FR 235 Trimmer

Provides the EC Declaration of Conformity for the STIHL FR 235 Trimmer.

Related product manuals

Stihl FR 235 User Manual

Table of Contents

Questions and Answers:

Stihl FR 235 Specifications

Summary

Guide to Using this Manual

Applicable Documentation

Symbols used with warnings in the text

Overview

Trimmer

Deflectors and Cutting Attachments

Safety Precautions

Warning Signs

Universal Deflector and Skirt

Intended Use

The Operator

Clothing and equipment

Working Area and Surroundings

Safe Condition

Deflector

Mowing Head

Metal cutting attachment

Fuel Mixture and Refueling

Working

Reactive forces

Transporting

Storing

Cleaning, Maintenance and Repair

Preparing Trimmer for Operation

Preparing Trimmer for Operation

Assembling the Trimmer

Assembling the Carrying System

Mounting the Powerhead

Mounting the Drive Tube

Mounting Loop Handle with Barrier Bar

Mounting and Removing the Deflector

Mounting and Removing the Mowing Head

Removing the Mowing Head

Removing and Installing Metal Cutting Attachment

Adjusting Trimmer for User

Fitting and Adjusting the Carrying System

Removing the Carrying System

Mixing Fuel and Refueling the Brushcutter

Mixing Fuel

Fueling the Trimmer

Starting and Stopping the Engine

Selecting the correct starting procedure

Preparing Engine for Start

Starting the Engine

Stopping the Engine

Testing the Trimmer

Checking the Controls

Operating the Trimmer

Adjusting Carburetor for Operation at High Altitude

Holding and Controlling the Trimmer

Mowing

After Finishing Work

When Work is Finished

Transporting

Transporting the brushcutter

Storing

Storing the Trimmer

Cleaning

Cleaning the Trimmer

Cleaning the Deflector and Cutting Attachment

Maintenance

Maintenance Intervals

Lubricating and Turning Around the Flexible Shaft

Lubricating the Gearbox

Adjusting the Throttle Cable

Sharpening and Balancing a Metal Cutting Attachment

Repairing

Repairing the Trimmer and Cutting Attachment

Troubleshooting Trimmer

Troubleshooting Trimmer

Replacing the Air Filter

Specifications

STIHL FR 235 Trimmer

Sound Values and Vibration Values

REACH