Stihl MS180 Chainsaw Manual

The Stihl MS180 is a lightweight, easy-to-use chainsaw designed for homeowners. It features a powerful 31.8cc engine, STIHL Quickstop® inertia chain brake, Ematic™ lubrication system, and STIHL ErgoStart™ for easier starting. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Engine, guide bar, saw chain, chain brake lever, throttle trigger, choke control, fuel and oil caps.

Feature	Description
Engine	31.8cc, 2-stroke, air-cooled gasoline engine
Guide Bar	Available in 16" or 18" lengths
Saw Chain	STIHL Picco Micro 3 (PM3) chain
Chain Brake	STIHL Quickstop® inertia-activated chain brake
Lubrication	Ematic™ system for efficient chain oil use
Starting System	STIHL ErgoStart™ for reduced pulling force
Fuel System	Diaphragm carburetor with purge bulb
Anti-Vibration	Reduced vibration handle system
Weight	Approximately 9.9 lbs (without bar and chain)
Warranty	Limited warranty for residential use

Safety Information

Read and understand all instructions before use. Always wear proper protective equipment.

1. Personal Protective Equipment (PPE): Always wear safety glasses, hearing protection, gloves, chainsaw chaps or pants, and sturdy boots.
2. Work Area Safety: Keep bystanders and pets at least 30 feet away. Ensure secure footing.
3. Chain Brake Check: Test chain brake function before each use.
4. Kickback Awareness: Understand kickback zone (upper quadrant of bar tip). Never cut with this area.

WARNING! Failure to follow safety instructions can result in serious injury or death. Never operate a chainsaw while tired, under the influence, or in poor weather conditions.

Assembly & Preparation

Assemble the chainsaw before first use.

1. Attach Guide Bar and Chain: Place bar on studs, loop chain around bar with cutters facing forward on top, adjust tension.
2. Fill Fuel Tank: Use fresh, high-quality gasoline mixed with STIHL HP Ultra 2-cycle oil at a 50:1 ratio.
3. Fill Chain Oil Tank: Use STIHL chain oil or a quality substitute. Check flow before cutting.
4. Check Chain Tension: Chain should be snug against bar but pull freely by hand.

CAUTION! Fuel is highly flammable. Refuel in a well-ventilated area with engine off and cool. Wipe up spills immediately.

Specifications

• Engine Displacement: 31.8 cc
• Power Output: 1.8 kW / 2.4 bhp
• Fuel Tank Volume: 8.5 fl. oz. (0.25 liter)
• Oil Tank Volume: 5.1 fl. oz. (0.15 liter)
• Recommended Guide Bar Lengths: 16" or 18"
• Chain Pitch/Gauge: 3/8" PM / .050" (1.3 mm)
• Weight (Powerhead only): 9.9 lbs (4.5 kg)
• Sound Pressure Level: 106 dB(A)
• Vibration Level (Front/Rear Handle): 4.5/3.5 m/s²

Controls and Components

Familiarize yourself with all controls before starting.

Right Side: Throttle trigger, throttle trigger lockout, rear handle, master control lever (combines choke, stop control, and run positions).

Left Side: Chain brake lever (front hand guard), chain tensioner, oil filler cap, fuel filler cap.

Top/Front: Muffler, spark plug, guide bar, chain catcher, chain sprocket cover.

Operation Controls: Master Control Lever (Stop-0, Run-I, Choke-full choke/cold start), Chain Brake Lever (push forward to engage/activate, pull back to disengage), Throttle Trigger Lockout (must be depressed to allow throttle activation).

Starting & Stopping

Starting (Cold Engine):

1. Engage chain brake by pushing lever forward.
2. Press decompression valve (if equipped).
3. Move master control lever to choke position (full down).
4. Press purge bulb 5-6 times until fuel is visible.
5. Place saw on ground, hold firmly with left hand on front handle, right foot in rear handle.
6. Pull starter rope briskly until engine fires (usually 2-5 pulls).
7. Immediately move master control lever up to run position (I).
8. Pull starter rope again to start engine.
9. Briefly blip throttle to disengage high-idle.

Starting (Warm Engine): Omit steps 3 and 7. Start with master control in run position (I).

Stopping: Release throttle, allow engine to idle. Move master control lever down to stop position (0).

Operation & Cutting Techniques

Always use proper cutting techniques to maintain control and reduce fatigue.

1. Basic Stance: Stand with feet shoulder-width apart, left foot slightly forward. Hold saw close to body.
2. Grip: Grip front handle with left hand, rear handle with right hand. Keep thumbs wrapped around handles.
3. Felling (Cutting Down a Tree): Plan escape path. Make notch cut (1/3 tree diameter), then back cut. Never cut above shoulder height.
4. Limbing (Removing Branches): Work from trunk outward. Let branches support saw weight. Beware of spring poles.
5. Bucking (Cutting Logs): Support log off ground. Cut from top, avoid pinching bar. Use wedges for large logs.

WARNING! Beware of kickback. Do not let the upper quadrant of the bar tip contact any object. Always hold saw firmly with both hands.

Maintenance & Cleaning

Regular maintenance ensures performance and longevity.

1. Daily/Before Use: Check chain tension, sharpness, and lubrication. Check fuel and oil levels. Inspect for loose parts or damage.
2. Air Filter: Clean regularly (more often in dusty conditions). Remove, tap clean, or wash in soapy water. Dry completely before reinstalling.
3. Spark Plug: Check and clean electrode gap (0.020") periodically. Replace if worn or fouled.
4. Muffler & Cooling Fins: Keep free of debris to prevent overheating.
5. Exterior Cleaning: Wipe down with a damp cloth. Never use pressurized water.

CAUTION! Always disconnect spark plug wire before performing any maintenance.

Chain Sharpening & Tensioning

A sharp, properly tensioned chain is essential for safe and efficient cutting.

Sharpening: Use a round file (5/32" or 4.0mm) and file guide. Maintain original 30° cutting angle. File all cutters to equal length. File depth gauges (rakers) with a flat file and gauge.

Tensioning: Loosen bar nuts. Turn tensioning screw clockwise until chain is snug against bar bottom but can be pulled around by hand. Tighten bar nuts while lifting bar tip. Re-check tension.

Tip: Chain should be tensioned when cold. It will expand when hot; re-check tension after initial use.

Storage

Prepare chainsaw for storage if not used for more than 30 days.

1. Drain fuel tank and run engine until it stops to clear carburetor.
2. Remove chain, clean, and soak in oil. Clean guide bar groove and oil holes.
3. Thoroughly clean entire saw.
4. Store in a dry, secure place, out of reach of children.

CAUTION! Old fuel can damage engine components. Always use fresh fuel mix.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine will not start	No fuel, flooded, bad spark, master control position	Check fuel, move control to run, check spark plug, wait if flooded.
Engine starts but dies	Clogged air filter, fuel filter, carburetor issues	Clean/replace air filter, check fuel line and filter.
Chain does not turn	Chain brake engaged, clutch issues, chain too tight	Disengage chain brake, check clutch, loosen chain tension.
Chain turns at idle	Idle speed too high	Adjust idle speed screw (consult dealer).
Poor cutting performance	Dull chain, improper filing, low chain oil	Sharpen chain correctly, check oil flow and tank level.
Excessive vibration	Loose parts, unbalanced chain, damaged AV mounts	Tighten all fasteners, check chain sharpness, inspect anti-vibration elements.

Service: For repairs beyond basic maintenance, contact an authorized STIHL servicing dealer.

Support: Visit www.stihlusa.com or contact your local STIHL dealer.