Stihl MS170 Owners Manual: A Comprehensive Guide
This manual details the Stihl MS170 chainsaw, offering crucial information for safe operation, maintenance, and repair, including parts lists and troubleshooting guides․
The Stihl MS170 is a lightweight, easy-to-use chainsaw ideal for homeowners and occasional users․ This manual provides essential guidance for maximizing performance and ensuring longevity․ It covers everything from initial assembly and safe starting procedures to detailed maintenance schedules․ Understanding this guide is crucial for operating the MS170 effectively and safely․
STIHL recommends using STIHL MotoMix fuel for optimal engine performance and reduced emissions․ Refer to the detailed sections for specific mixing ratios and maintenance instructions․
Safety Precautions
Always prioritize safety when operating the Stihl MS170․ Before each use, inspect the chainsaw for damage and ensure all safety features are functional, including the chain brake and guards․ Wear appropriate personal protective equipment (PPE), such as safety glasses, hearing protection, gloves, and chaps․
Never operate the chainsaw with a damaged or dull chain․ Always stop the engine before performing any maintenance or adjustments․ Be aware of your surroundings and maintain a safe distance from others․
Understanding the Components
The Stihl MS170 consists of several key components crucial for operation․ These include the engine, fuel tank, chain, bar, chain brake, throttle control, anti-vibration system, and air filter․ Familiarize yourself with the location and function of each part․
Understanding these elements is vital for proper maintenance and safe operation․ The illustrated parts list (detailed later) provides a visual guide to identify each component accurately for repairs or replacements․
Identifying Key Parts
Essential parts of the MS170 include the chain brake lever, stopping the chain immediately for safety․ The throttle trigger controls engine speed, while the on/off switch manages operation․ Locate the choke control for cold starts and the decompression lever to ease pulling the starter cord․
Recognizing the fuel tank, air filter cover, and spark plug cover is also important for maintenance․ Refer to the illustrated parts list for a detailed visual guide to each component’s location․
Chain and Bar Basics
The chain’s cutters engage the wood, while the drive links connect to the sprocket․ Understanding chain pitch and gauge is vital for proper selection and performance․ The bar provides support and guides the chain; rail maintenance prevents binding․
Regular inspection reveals wear, damage, and ensures optimal cutting efficiency․ Proper chain tension minimizes kickback risk and extends both chain and bar lifespan․ Always use a Stihl-recommended chain for compatibility․
Assembly Instructions
Before first use, carefully attach the bar and chain, ensuring correct orientation․ The bar should be securely mounted with the drive sprocket facing the engine․ Proper chain installation dictates the cutters face in the direction of bar rotation․
Adjust the chain tension according to the manual’s guidelines․ Verify the chain brake functions correctly and the throttle operates smoothly․ Double-check all fasteners are tightened before starting the engine for initial operation․
Starting the Stihl MS170
Always ensure the chainsaw is on a flat, stable surface before attempting to start it․ Engage the chain brake for safety․ For a cold start, set the choke lever and prime the fuel bulb several times․ Then, firmly pull the starter cord until the engine fires․
For a warm start, disengage the choke․ Pull the starter cord smoothly; avoid jerking․ Always use STIHL MotoMix fuel for optimal performance and longevity of the engine․
Fueling and Mixing Ratios (STIHL MotoMix)
STIHL recommends using STIHL MotoMix fuel, a pre-mixed blend of gasoline and high-quality 2-stroke engine oil․ This ensures optimal engine performance and reduces emissions․ If mixing your own fuel, use a 50:1 ratio – 50 parts gasoline to 1 part STIHL 2-stroke oil․
Always use fresh fuel and avoid spilling․ Properly store fuel in an approved container, away from heat sources and open flames․ Never use fuel containing more than 10% ethanol․
Cold Start Procedure
To cold start the MS170, ensure the chain brake is engaged and the engine switch is set to ‘ON’․ Prime the carburetor by pressing the primer bulb several times until fuel is visible․ Set the choke lever to the ‘start’ position․ Firmly grasp the starter handle and pull the cord with a smooth, deliberate motion․
Repeat pulling until the engine starts, then disengage the choke․
Warm Start Procedure
For a warm start, disengage the choke lever and ensure the chain brake remains engaged․ Firmly grasp the starter handle and pull the cord with a smooth, consistent motion – typically requiring less effort than a cold start․ If the engine doesn’t start immediately, try a second pull․
Avoid excessive pulling to prevent fuel flooding․
Operating Instructions
Always maintain a firm grip with both hands while operating the Stihl MS170, keeping a safe distance from the chain․ Ensure a stable stance and be aware of your surroundings, checking for obstacles and potential hazards; Utilize proper cutting techniques, avoiding pinching the bar and maintaining control throughout each cut․
Prioritize safety and follow all precautions․
Proper Cutting Techniques
When felling trees, notch cutting is essential for controlled direction․ Begin with an open-faced notch on the side you want the tree to fall, followed by a back cut slightly higher․ Avoid complete severance during the back cut to maintain a hinge for control․
For limbing and bucking, use the appropriate cutting angles and avoid pinching the bar․ Always plan your cuts and be mindful of kickback zones․
Safe Handling Practices
Always wear appropriate personal protective equipment (PPE), including a helmet, eye protection, hearing protection, gloves, and chainsaw chaps․ Maintain a firm grip with both hands, keeping your body to the side of the cutting plane․
Be aware of kickback, a sudden, uncontrolled upward or backward movement of the chainsaw․ Never cut above shoulder height and avoid contact with hidden objects․
Chain Maintenance
Regular chain maintenance is vital for performance and safety․ This includes frequent sharpening to maintain cutting efficiency and proper tension adjustment to prevent derailment or damage․ A dull chain requires more force, increasing kickback risk․
Inspect the chain regularly for damage, cracks, or worn teeth․ Replace the chain when necessary․ Proper chain maintenance extends the life of both the chain and the bar․
Sharpening the Chain
Maintaining sharp cutting teeth is crucial for efficient operation․ Use a round file of the correct size, guided by a sharpening guide, to restore the proper cutting angle․ Ensure all teeth are sharpened to the same length for balanced cutting․
File each tooth with smooth, even strokes, avoiding overheating․ Regularly check the depth gauges and file them down if necessary to maintain optimal performance․ A properly sharpened chain significantly reduces user fatigue․
Chain Tension Adjustment
Proper chain tension is vital for safe and efficient cutting․ A too-loose chain can derail, while a too-tight chain causes excessive wear․ Adjust tension using the chain tensioning screw on the chain cover․
With the chain brake engaged, loosen the screw, adjust the tension until the drive links sit snugly in the bar groove, and retighten the screw․ Check tension frequently during use, especially when new․
Bar Maintenance
Maintaining your guide bar ensures optimal chainsaw performance and prolongs its lifespan․ Regularly inspect the bar for wear, damage, and burrs․ Clean the bar groove after each use to remove sawdust and debris, preventing binding and ensuring smooth chain movement․
Periodically check and file the bar rails to maintain squareness, which is crucial for proper chain alignment and cutting efficiency․ A worn or damaged bar should be replaced promptly․
Cleaning the Bar
Regularly cleaning the guide bar is essential for efficient operation․ After each use, remove the chain and thoroughly clean the bar groove with a scraper or brush, eliminating accumulated sawdust, pitch, and wood debris․ This prevents binding and ensures smooth chain travel․
Inspect the bar rails for buildup and clean them as needed․ A clean bar minimizes friction and extends both bar and chain life, contributing to safer and more effective cutting․
Bar Rail Maintenance
Maintaining the bar rails ensures optimal chain function and prolongs bar life․ Regularly check the rails for wear, burrs, or damage․ Use a flat file to carefully remove any burrs or irregularities, ensuring smooth chain travel along the rails․
Properly maintained rails reduce friction and prevent the chain from binding or derailing․ Inspect for proper oil flow; clogged oil holes hinder lubrication, accelerating wear․ Consistent rail maintenance is vital for safe operation․
Air Filter Maintenance
A clean air filter is crucial for engine performance and longevity․ Regularly inspect the air filter for dirt and debris; a clogged filter restricts airflow, reducing power and increasing fuel consumption․ Cleaning involves gently tapping or brushing away loose particles․
For thorough cleaning, wash the filter in warm, soapy water, rinse completely, and allow it to dry fully before reinstalling․ Replace the filter when it becomes damaged or excessively dirty, ensuring optimal engine operation․
Cleaning the Air Filter
Regularly cleaning the air filter maintains optimal engine performance․ Begin by removing the filter cover and carefully extracting the filter element․ Gently tap the filter on a clean surface to dislodge loose dirt and debris․ Avoid using compressed air, as it can embed particles deeper into the filter material․
For a more thorough clean, wash the filter in warm, soapy water, ensuring it’s fully rinsed and completely dry before reinstallation․
Replacing the Air Filter
Over time, the air filter will become clogged and require replacement for optimal engine function․ First, remove the filter cover and the old filter element․ Ensure the new filter is the correct part for your Stihl MS170 model․ Carefully install the new filter, ensuring a proper seal against the air filter housing․
Reattach the filter cover securely to prevent unfiltered air from entering the engine․ Regular replacement extends engine life․
Spark Plug Maintenance
Maintaining the spark plug is vital for reliable engine starting and performance․ Regularly inspect the spark plug for fouling, wear, or damage․ A properly functioning spark plug ensures efficient combustion․ If the electrode is worn or carbon-fouled, replacement is necessary․ Use the specified spark plug for your MS170 model․
Ensure the spark plug gap is correct before installation for optimal ignition․
Inspecting the Spark Plug
Regular spark plug inspection is crucial for engine health․ Disconnect the spark plug wire before inspection․ Examine the electrode for carbon buildup, wear, or oil fouling․ A light tan or gray color indicates proper combustion․ Black, sooty deposits suggest a rich fuel mixture, while a white or blistered electrode indicates a lean mixture․
Check for cracked or damaged porcelain insulation․ Replace if any issues are found․
Replacing the Spark Plug
Always disconnect the spark plug wire before replacement․ Use a spark plug wrench to carefully remove the old plug․ Check the gap of the new spark plug – consult your manual for the correct specification (typically 0․5mm or 0․020″)․
Thread the new plug in by hand to avoid cross-threading, then tighten it with the wrench to the specified torque․ Reconnect the spark plug wire securely․
Fuel System Maintenance
Regular fuel system maintenance ensures optimal engine performance․ Periodically replace the fuel filter to prevent debris from clogging the carburetor․ Use fresh STIHL MotoMix fuel for best results, avoiding outdated or contaminated fuel․
Basic carburetor adjustments may be needed if the engine runs poorly; however, complex adjustments should be performed by a qualified technician․ Always follow safety precautions when working with fuel․
Fuel Filter Replacement
A clogged fuel filter restricts fuel flow, impacting performance․ To replace, carefully remove the fuel tank cap and extract the filter located within the tank․ Inspect the old filter for debris and ensure the new filter is correctly seated․
Avoid spilling fuel during this process and always work in a well-ventilated area․ Regular replacement – typically annually – maintains a clean fuel supply for reliable operation․
Carburetor Adjustments (Basic)
Basic carburetor adjustments impact idle speed and mixture․ Locate the adjustment screws – typically labeled ‘H’ (high speed) and ‘L’ (low speed)․ Minor adjustments can resolve starting issues or rough running․
Turn screws clockwise to decrease, counterclockwise to increase․ Avoid excessive adjustments; significant changes require professional servicing․ Always consult a qualified technician for complex carburetor work to prevent damage․
Troubleshooting Common Issues
Common problems with the Stihl MS170 include starting difficulties and chain stoppage․ If the engine won’t start, check fuel levels, spark plug condition, and air filter cleanliness․ A flooded engine requires removing the spark plug and pulling the starter cord repeatedly․
Chain stoppage often indicates insufficient chain tension or a clogged bar groove․ Always prioritize safety and consult the full manual for detailed diagnostics and repair procedures․
Engine Won’t Start
If your Stihl MS170 fails to start, several factors could be at play․ First, verify adequate fuel and a correctly mixed fuel-to-oil ratio using STIHL MotoMix․ Inspect the spark plug for fouling or damage, replacing it if necessary․ A clogged air filter restricts airflow, hindering ignition․
A flooded engine requires removing the spark plug and repeatedly pulling the starter cord․ Ensure the choke is properly engaged for cold starts․
Chain Stops During Cutting
If the chain halts mid-cut, a common cause is insufficient chain tension․ Adjust the tensioner until the chain moves freely around the bar without excessive slack․ A dull chain significantly increases resistance, leading to stalling; sharpen it promptly․ Check for obstructions like pinched wood or embedded debris․
Ensure proper chain lubrication; a dry chain generates excessive friction․ Inspect the chain brake for accidental engagement, and verify the carburetor isn’t clogged․
Storage and Transport
For extended storage, drain the fuel tank completely to prevent carburetor issues․ Clean the saw thoroughly, removing sawdust and debris․ Store in a dry, secure location inaccessible to children, ideally with a protective sheath over the bar and chain․
During transport, engage the chain brake and utilize a scabbard․ Secure the chainsaw to prevent movement and potential injury․ Avoid transporting with fuel in the tank if possible, adhering to local regulations․
Illustrated Parts List Overview
The illustrated parts list is a vital resource for identifying and ordering replacement components for your Stihl MS170․ It provides detailed diagrams showcasing each part’s location and corresponding part number․ Accessing this list, often available as a PDF (like the Tronconneuse Stihl ms170 Liste-Des-Pieces PDF), simplifies repairs․
Utilize the part numbers when contacting a Stihl dealer to ensure accurate ordering․ Regularly consult the list during maintenance to understand the chainsaw’s internal structure․
Warranty Information
Your Stihl MS170 is covered by a limited warranty against defects in materials and workmanship from the date of purchase․ Warranty duration varies, so carefully review the specific terms provided with your chainsaw․ Proper maintenance, as outlined in this manual, is crucial for warranty validity․
Unauthorized modifications or repairs may void the warranty․ Contact an authorized Stihl dealer for warranty claims and service; retain your proof of purchase․