Stihl MS310 Manual

The Stihl MS310 is a professional-grade chainsaw featuring a powerful 59.0 cc engine, STIHL Quickstop® inertia chain brake, anti-vibration system, side-access chain tensioner, decompression valve for easier starting, and a fuel-efficient engine design. Below are key sections for safety, features, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 59.0 cc engine, STIHL Quickstop® inertia chain brake, anti-vibration system, side-access chain tensioner, decompression valve, and fuel-efficient design.

Feature	Description
Engine Displacement	59.0 cc professional-grade engine
Chain Brake	STIHL Quickstop® inertia-activated chain brake
Anti-Vibration System	Reduces operator fatigue during extended use
Chain Tensioner	Side-access for easy chain adjustment
Decompression Valve	Reduces compression for easier starting
Fuel System	Fuel-efficient design with automatic oiling
Guide Bar Length	Typically 18" or 20" (check specific model)
Weight (powerhead)	Approximately 13.2 lbs (without bar and chain)
Ignition System	Electronic ignition with single-lever master control
Air Filtration	STIHL pre-separation air filtration system

Safety Information

Always wear proper protective equipment and follow safety guidelines.

1. Personal Protective Equipment: Wear safety glasses, hearing protection, gloves, chainsaw chaps, and sturdy boots.
2. Work Area Safety: Clear work area of obstacles and ensure secure footing.
3. Chain Brake Test: Test chain brake function before each use.
4. Fuel Safety: Mix fuel outdoors, away from ignition sources.

WARNING! Chainsaws are dangerous tools. Never operate without proper training and safety gear. Keep bystanders at a safe distance.

Assembly & Preparation

Assemble your chainsaw following these steps.

1. Attach guide bar and chain: Place bar on studs, align chain with sprocket, adjust tension.
2. Fill fuel tank: Use STIHL MotoMix® or mix 50:1 with STIHL HP Ultra oil and 89+ octane gasoline.
3. Fill chain oil tank: Use STIHL chain oil or equivalent.
4. Check chain tension: Chain should be snug against bar but pull freely.

CAUTION! Ensure chain is properly installed with cutting teeth facing forward. Overtightening can damage bar and chain.

Specifications

• Engine Displacement: 59.0 cc
• Power Output: 3.4 kW (4.6 hp)
• Fuel Capacity: 24.3 oz (720 ml)
• Oil Capacity: 11.8 oz (350 ml)
• Weight (powerhead): 13.2 lbs (6.0 kg)
• Guide Bar Lengths: 18" - 20" (45-50 cm)
• Chain Pitch: 3/8"
• Chain Gauge: .050" (1.3 mm)
• Ignition: STIHL Electronic Ignition (CDI)
• Sound Pressure Level: 106 dB(A)

Controls and Components

Master Control Lever: Combines choke, throttle lock, and stop functions. Front Handle: Contains throttle trigger and throttle lockout. Rear Handle: Contains master control lever and start/stop switch.

Main Components: Chain brake handle, decompression valve, fuel cap, oil cap, chain tensioner, spark plug, air filter cover, muffler.

Operation: Master control positions: STOP (0), RUN (I), CHOKE (closed position for cold start). Chain brake: Push forward to engage, pull back to disengage. Throttle lockout: Must be depressed before throttle trigger can be engaged.

Starting & Stopping

Starting Procedure (Cold Engine):

1. Engage chain brake by pushing handle forward.
2. Set master control lever to choke position (full down).
3. Press decompression valve (if equipped).
4. Place saw on ground, hold rear handle with right foot.
5. Pull starter rope briskly until engine fires.
6. Move master control to half-throttle position.
7. Pull starter rope until engine starts.
8. Briefly blip throttle to disengage fast idle.

Stopping: Release throttle, move master control to STOP position.

Operation Guidelines

Proper cutting techniques for safe and efficient operation.

1. Secure footing: Maintain balanced stance with feet shoulder-width apart.
2. Grip: Hold front handle with left hand, rear handle with right hand.
3. Starting cut: Apply light pressure, let chain do the work.
4. Kickback zone: Avoid cutting with upper quadrant of bar tip.
5. Pushing/pulling: Use proper techniques for different cutting situations.

Tip: Keep chain sharp and properly tensioned. Let the saw work at its own pace - don't force it.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

1. Daily: Check chain tension, sharpness, and lubrication.
2. Weekly: Clean air filter, check spark plug, clean cooling fins.
3. Monthly: Clean fuel filter, check anti-vibration elements.
4. Seasonally: Replace spark plug, clean exhaust screen, check all fasteners.
5. Annually: Professional servicing recommended for heavy users.

WARNING! Always disconnect spark plug before performing maintenance. Use only STIHL-approved replacement parts.

Chain & Bar Care

Proper chain and bar maintenance is essential for safe operation.

Chain Sharpening: Use appropriate round file size (typically 5/32" for 3/8" pitch). Maintain correct filing angle (30°). File all cutters to equal length. Check depth gauges regularly.

Bar Maintenance: Clean bar groove weekly. Flip bar regularly for even wear. Check for wear and straightness. Lubricate sprocket nose if equipped.

CAUTION! Always wear gloves when handling chain. A dull chain requires more force and increases kickback risk.

Storage Guidelines

Proper storage prevents fuel system issues and corrosion.

1. Short-term (under 30 days): Fill fuel tank to prevent condensation.
2. Long-term: Drain fuel tank completely. Run engine until it stops to clear carburetor.
3. Remove chain: Clean and oil chain, store separately.
4. Clean entire saw: Remove debris from cooling fins and air intake.
5. Store in dry place: Cover to prevent dust accumulation.

Important: Never store with fuel in tank for more than 30 days. Use fuel stabilizer if necessary.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	Fuel issues, spark plug, flooded	Check fuel mix, spark plug gap, use cold start procedure.
Engine runs poorly	Dirty air filter, carb adjustment	Clean/replace air filter, check carburetor settings.
Chain won't oil	Empty oil tank, clogged ports	Fill oil tank, clean oil ports, check oil pump.
Chain comes off bar	Loose chain, worn bar	Adjust chain tension, inspect bar for wear.
Excessive vibration	Loose components, damaged AV mounts	Tighten all fasteners, check anti-vibration elements.
Overheating	Dirty cooling fins, lean mixture	Clean cooling fins, check carburetor adjustment.

Service: For professional service, contact authorized STIHL dealer. Use only genuine STIHL parts.

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