Stihl MS 311 Manual

The Stihl MS 311 is a professional-grade chainsaw featuring a powerful 59.0 cc engine, STIHL Quickstop® inertia chain brake, Ematic™ lubrication system, and a side-access chain tensioner. Designed for demanding cutting tasks, it offers excellent power-to-weight ratio, low vibration, and easy maintenance. Below are key sections for safety, features, operation, maintenance, and troubleshooting.

Features at a Glance

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

Feature	Description
Engine Displacement	59.0 cc, 2-stroke engine
Power Output	3.4 kW (4.6 bhp)
Guide Bar Lengths	16" to 20" (recommended)
Chain Brake	STIHL Quickstop® inertia activated
Lubrication System	Ematic™ for reduced oil consumption
Anti-Vibration System	Reduces operator fatigue
Decompression Valve	Easier starting
Fuel Tank Capacity	700 ml (23.7 fl. oz.)
Oil Tank Capacity	300 ml (10.1 fl. oz.)
Weight (powerhead)	6.2 kg (13.7 lbs)

Safety Information

Read and understand all safety warnings before operation.

1. Personal Protective Equipment (PPE): Always wear chainsaw chaps, safety glasses, hearing protection, gloves, and steel-toed boots.
2. Work Area Safety: Clear area of bystanders, especially children. Ensure secure footing.
3. Chain Brake Check: Verify proper function before each use.
4. Kickback Awareness: Be aware of kickback zone; use reduced-kickback chain.

WARNING! Failure to follow safety instructions can result in serious injury or death. Never operate a chainsaw without proper training.

Assembly & Preparation

Assemble chainsaw before first use.

1. Attach Guide Bar & Chain: Place bar on studs, fit chain with drive links in bar groove, tension correctly.
2. Fill Fuel: Use STIHL MotoMix® or mix 50:1 with STIHL HP Ultra oil and 89+ octane gasoline.
3. Fill Chain Oil: Use STIHL chain oil or equivalent.
4. Check Controls: Ensure throttle trigger, throttle lockout, and chain brake function properly.

CAUTION! Use only STIHL-approved fuel and oil mixtures. Improper fuel can damage engine.

Specifications

• Engine Type: 2-stroke, single cylinder.
• Displacement: 59.0 cc.
• Power Output: 3.4 kW (4.6 bhp).
• Max Engine Speed: 13,500 rpm.
• Idle Speed: 2,800 rpm.
• Fuel/Oil Ratio: 50:1 (STIHL HP Ultra).
• Sound Pressure Level: 106 dB(A).
• Vibration Level: Left/Right: 3.2 m/s², Front/Rear: 2.8 m/s².
• Warranty: Limited warranty for professional use.

Controls and Components

Main Controls: Front Handle with throttle trigger and lockout, Rear Handle, Chain Brake lever, Master Control Lever (combines choke, stop switch, and decompression valve), Fuel Cap, Oil Cap, and Side-access Chain Tensioner.

Master Control Lever Positions: STOP (0): Engine off. RUN (I): Normal operation. START (Choke symbol): Cold start position. Decompression valve button reduces cylinder pressure for easier starting.

Maintenance Points: Air filter cover, Spark plug, Chain tensioner, Muffler.

Starting & Stopping

Cold Start:

1. Engage chain brake. Set Master Control to START (choke).
2. Press decompression valve (if equipped).
3. Place saw on ground, hold rear handle with right foot.
4. Pull starter handle until engine fires (usually 2-5 pulls).
5. Move Master Control to RUN. Pull starter to start engine.
6. Blip throttle to disengage fast idle.

Warm Start: Master Control to RUN. Pull starter.

Stopping: Release throttle. Move Master Control to STOP (0).

Operation & Cutting Techniques

Basic Cutting: Use full throttle when cutting. Let chain do the work; don't force.

1. Felling: Plan escape path. Use notch and back cut techniques.
2. Limbing: Stand uphill. Cut from top of log, supporting limb if needed.
3. Bucking: Support log. Cut from top, avoid pinching chain.
4. Kickback Prevention: Keep saw body close to you. Do not cut with bar tip.

Tip: Maintain sharp chain. Dull chain increases effort and risk.

Maintenance Schedule

Daily/Before Use: Check chain tension, sharpness, and lubrication. Check fuel and oil levels. Inspect for loose parts.

Weekly: Clean air filter. Check spark plug. Clean cooling fins and muffler area.

Monthly: Clean fuel filter. Check anti-vibration elements. Inspect bar for wear.

Annually: Have servicing done by authorized STIHL dealer.

Chain & Bar Care

Chain Sharpening: Use correct round file size. Maintain proper filing angle (typically 30°). File all cutters evenly.

Bar Maintenance: Clean bar groove. Flip bar regularly for even wear. Check for burrs on rails.

Lubrication: Ensure oiler is working. Chain should throw off fine oil mist during operation.

CAUTION! Always wear gloves when handling chain. Chain is extremely sharp.

Storage

Long-term Storage: Empty fuel tank and run engine dry. Remove chain, clean, and soak in oil. Clean entire saw. Store in dry, secure place.

WARNING! Never store chainsaw with fuel in tank for more than 30 days. Fuel can degrade and damage engine.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No spark, flooded, old fuel	Check spark plug; use fresh fuel; follow cold start procedure.
Engine runs poorly	Dirty air filter, clogged fuel filter	Clean/replace air filter; replace fuel filter.
Chain doesn't turn	Chain brake engaged, clutch worn	Disengage chain brake; inspect clutch.
Excessive vibration	Loose parts, unbalanced chain	Tighten all fasteners; sharpen chain evenly.
Chain not oiling	Empty oil tank, clogged oiler	Fill oil tank; clean oil passage; check oil pump.

Service: For major repairs, contact authorized STIHL dealer.

Support: STIHL USA, 1-800-467-8445, www.stihlusa.com