MS290 Stihl Manual

The Stihl MS290 is a professional-grade chainsaw featuring a powerful 56.5cc engine, anti-vibration system, QuickStop chain brake, Ematic lubrication system, and STIHL Easy2Start technology. Designed for demanding cutting tasks including felling, limbing, and bucking. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Engine, guide bar, cutting chain, chain brake, throttle trigger, master control lever, fuel tank, oil tank.

Feature	Description
Engine	56.5cc 2-stroke engine with electronic ignition
Anti-Vibration System	Reduces operator fatigue during extended use
QuickStop Chain Brake	Inertia-activated safety brake
Ematic Lubrication	Efficient oil delivery system for chain and bar
Easy2Start	Reduces pulling force required for starting
Master Control Lever	Single lever for choke, run, and stop positions
Decompression Valve	Reduces compression for easier starting
Chain Tensioner	Side-access for quick chain adjustment
Fuel Tank Capacity	16.9 fl. oz. (500 ml)
Oil Tank Capacity	8.5 fl. oz. (250 ml)

Assembly & Preparation

Unpack and inspect all components. Assemble on clean, flat surface.

1. Attach guide bar: Remove bar cover nuts, position bar, align chain, replace nuts.
2. Install chain: Ensure cutting teeth face forward on top of bar.
3. Adjust chain tension: Use side tensioner; proper tension when chain snaps back.
4. Fill fuel tank: Mix STIHL 2-stroke oil with unleaded gasoline (50:1 ratio).
5. Fill oil tank: Use STIHL chain oil or equivalent.

WARNING! Always wear protective gear: gloves, eye protection, hearing protection, chainsaw chaps, and steel-toe boots.

First-Time Operation

Perform pre-start checks before operation.

1. Check chain tension: Adjust if loose.
2. Inspect chain sharpness: Replace or sharpen if dull.
3. Check fuel and oil levels: Fill as needed.
4. Start engine: Set master control to choke, pull starter rope until engine fires, move to run position, pull again.
5. Warm up: Allow engine to idle for 30 seconds before cutting.

CAUTION! Never start chainsaw unless bar and chain are properly installed and tensioned.

Specifications

• Engine Displacement: 56.5 cc
• Power Output: 3.5 bhp
• Fuel Capacity: 16.9 fl. oz. (500 ml)
• Oil Capacity: 8.5 fl. oz. (250 ml)
• Guide Bar Lengths: 16", 18", 20" (available options)
• Chain Pitch: 3/8"
• Chain Gauge: .050"
• Weight (powerhead): 12.8 lbs (5.8 kg)
• Sound Pressure: 106 dB(A)
• Vibration Levels: Front 4.5 m/s², Rear 4.0 m/s²

Controls and Functions

Master Control Lever: Controls choke (cold start), run (normal operation), and stop (engine off). Throttle Trigger: Controls engine speed. Throttle Trigger Lockout: Must be depressed to access throttle. Chain Brake Lever: Manual activation; also inertia-activated. Decompression Valve: Reduces compression for easier starting. Chain Tensioner: Side-mounted adjustment screw.

Starting Procedure: Set master control to choke, pull starter rope until engine fires, move to run position, pull again to start. For warm engine, start in run position.

Chain & Bar Setup

Proper chain installation and tensioning critical for safety and performance.

1. Loosen bar nuts with combination wrench.
2. Position bar on studs, ensuring proper alignment.
3. Install chain with cutters facing forward on top of bar.
4. Tighten bar nuts finger-tight.
5. Adjust tension using side screw until chain snaps back when pulled from bar.
6. Retighten bar nuts securely.

Tip: Check chain tension frequently during first hour of use as new chain stretches.

Cutting Techniques

Proper techniques ensure safety and efficiency.

1. Felling: Plan escape path, make notch cut, then felling cut leaving hinge.
2. Limbing: Work from trunk outward, keep saw on ground side of log.
3. Buckling: Support log properly, cut from top down, avoid pinching.
4. Kickback prevention: Maintain firm grip, avoid tip contact, use reduced-kickback chain.

WARNING! Always be aware of kickback zone (upper quadrant of bar tip). Never cut with tip.

Maintenance Schedule

Daily: Clean air filter, check chain tension and sharpness, inspect bar for wear. Weekly: Clean cooling fins, check spark plug, clean fuel filter. Monthly: Clean carburetor air passage, check anti-vibration elements, inspect clutch and sprocket. As needed: Replace worn chain, bar, sprocket.

Storage & Transport

For storage: Empty fuel tank, run engine dry, remove chain and clean, store in dry place. For transport: Install scabbard on bar, engage chain brake, secure in vehicle.

CAUTION! Never store chainsaw with fuel in tank for extended periods. Use fuel stabilizer if necessary.

Safety Information

Always wear PPE: helmet with face shield, hearing protection, gloves, chainsaw chaps, steel-toe boots. Maintain safe distance from others. Never operate above shoulder height. Be aware of falling hazards. Keep hands away from chain at all times. Use proper fueling procedures.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	Fuel issues, spark plug, flooded	Check fuel mix, spark plug gap, use decompression valve if flooded.
Engine runs poorly	Dirty air filter, carburetor	Clean/replace air filter, adjust carburetor screws.
Chain doesn't turn	Brake engaged, clutch, sprocket	Disengage brake, inspect clutch springs, check sprocket wear.
Excessive vibration	Loose components, AV mounts	Tighten all fasteners, inspect anti-vibration elements.
Chain throws oil	Oil pump, tank vent	Adjust oil flow, clean tank vent, check oil type.
Chain dulls quickly	Dirty wood, improper filing	Clean cutting area, sharpen at correct angle, check depth gauges.

Service: Authorized STIHL dealers only. For dealer locator: 1-800-467-8445 or www.stihlusa.com