Stihl 290 Farm Boss Manual

The Stihl 290 Farm Boss is a professional-grade chainsaw designed for demanding farm and ranch work. It features a powerful engine, robust construction, advanced safety systems, and ergonomic design for extended use. Below are key sections covering safety, features, operation, maintenance, troubleshooting, and specifications.

1. Features at a Glance 2. Safety Information 3. Assembly & First-Time Setup 4. Specifications 5. Controls and Components 6. Operation Instructions 7. Maintenance Schedule 8. Chain Sharpening & Tensioning 9. Storage Guidelines 10. Warranty Information 11. Troubleshooting

Features at a Glance

Key components: STIHL 2-stroke engine, Quickstop® inertia chain brake, decompression valve, side-access chain tensioner, anti-vibration system, and ergonomic handles.

Feature	Description
Engine Displacement	56.5 cc
Power Output	3.4 bhp (2.5 kW)
Guide Bar Lengths	16" to 20" (standard 18")
Fuel Tank Capacity	16.9 fl. oz. (500 ml)
Oil Tank Capacity	11.1 fl. oz. (330 ml)
Weight (powerhead)	12.8 lbs (5.8 kg)
Ignition System	Electronic, capacitor discharge
Chain Brake System	Quickstop® inertia activated
Anti-Vibration	STIHL Advanced Damping System
Starting System	STIHL ElastoStart with decompression valve

Safety Information

Read and understand all safety warnings before operation.

Always wear proper PPE: safety glasses, hearing protection, gloves, chainsaw chaps, and steel-toe boots.
Clear work area of obstacles and bystanders before starting.
Never operate with damaged or missing safety devices.
Maintain secure footing and balance at all times.
Use the chain brake when carrying the saw or moving between cuts.

WARNING! Kickback can occur without warning. Always grip saw firmly with both hands. Never operate above shoulder height.

Assembly & First-Time Setup

Unpack and inspect all components. Assembly requires guide bar and chain installation.

Attach guide bar: Remove side cover, position bar over studs, align chain sprocket.
Install chain: Place chain over bar with cutters facing forward, engage drive links in sprocket.
Tension chain: Use side-access adjuster until chain snaps back when pulled from bar.
Mix fuel: Use STIHL 2-stroke oil with unleaded gasoline (50:1 ratio).
Fill tanks: Add fuel mix to fuel tank and STIHL chain oil to oil tank.

CAUTION! Use only STIHL-approved bar, chain, and lubricants. Incorrect fuel mix can cause engine damage.

Specifications

Model: STIHL MS 290 Farm Boss
Engine Type: Single cylinder, 2-stroke, air-cooled
Displacement: 56.5 cc (3.45 cu. in.)
Powerhead Weight: 12.8 lbs (5.8 kg)
Fuel/Oil Ratio: 50:1 (STIHL 2-Stroke Oil)
Idle Speed: 2,800 RPM
Maximum Power Speed: 9,000 RPM
Sound Pressure Level: 106 dB(A)
Vibration Levels (front/rear): 4.5/2.5 m/s²
Warranty: Limited 1-year consumer / 90-day commercial

Controls and Components

Main controls located on top and rear handle. Front Handle: Chain brake lever, hand guard. Rear Handle: Throttle trigger, throttle lockout, master control lever.

Master Control Lever (3-in-1): Choke/start position (⬆), run position (—), stop position (0).

Chain Brake: Manual activation via front hand guard; inertia activation via kickback. Decompression Valve: Reduces pulling force during starting. Chain Catcher: Prevents broken chain from striking operator. Muffler: Spark-arresting screen included. Side-access Chain Tensioner: Allows adjustment without tools.

Operation Instructions

Starting Procedure (Cold Engine):

Engage chain brake by pushing hand guard forward.
Set master control lever to choke position (⬆).
Press decompression valve (if equipped).
Place saw on firm ground, hold rear handle with right foot.
Pull starter handle slowly until engagement, then briskly 3-5 times.
Move master control to run position (—) and pull until engine starts.
Blip throttle to disengage fast idle.
Disengage chain brake by pulling hand guard toward you.

Tip: For warm restart, set master control to run position (—) only.

Maintenance Schedule

Daily/Before Use: Check chain tension, sharpness, and lubrication. Clean air filter, check for loose fasteners.

Interval	Task
Every 10 hours	Clean spark plug, check electrode gap (0.020")
Every 20 hours	Clean cylinder fins, check fuel filter
Every 50 hours	Replace spark plug, clean muffler screen
Every 100 hours	Check piston/cylinder through exhaust port
Annually	Replace fuel line, impulse line, and carburetor diaphragm

WARNING! Always disconnect spark plug before performing maintenance.

Chain Sharpening & Tensioning

Proper chain maintenance ensures optimal performance and safety.

Sharpening: Use round file matching chain pitch (typically 3/8"). Maintain 30° filing angle.
Depth gauges: File rakers to 0.025" below cutters using depth gauge tool.
Tensioning: Chain should snap back when pulled from bar. Adjust with side-access knob.
Lubrication: Always use STIHL chain oil. Check oil flow by running saw over light surface.

CAUTION! Never operate with loose or overtightened chain. Replace worn or damaged chains immediately.

Storage Guidelines

For storage over 30 days:

Drain fuel tank and run engine until it stops.
Remove spark plug and add 1 teaspoon of oil through spark plug hole.
Pull starter rope slowly to distribute oil, then reinstall plug.
Clean entire saw, especially cooling fins and air filter.
Store in dry place, cover to prevent dust accumulation.

CAUTION! Never store with fuel in tank. Fuel deteriorates and can damage carburetor.

Warranty Information

STIHL Limited Warranty: 1 year for consumer use, 90 days for commercial/rental use. Warranty covers defects in materials/workmanship. Not covered: normal wear, misuse, improper maintenance, non-STIHL parts. Proof of purchase required. For warranty service, contact authorized STIHL dealer. For support, visit www.stihlusa.com or call 1-800-467-8445.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	Old fuel, flooded, spark plug	Use fresh fuel mix; remove plug and dry; check spark.
Engine runs then dies	Fuel filter, vent, carburetor	Replace fuel filter; check tank vent; clean carburetor.
Poor cutting performance	Dull chain, improper tension	Sharpen chain; adjust tension; check lubrication.
Chain won't turn	Brake engaged, clutch, sprocket	Disengage chain brake; check clutch springs; replace sprocket.
Excessive vibration	Loose parts, unbalanced chain	Tighten all fasteners; replace damaged chain.
Chain throws oil	Overfilled, wrong oil, pump	Check oil level; use STIHL oil; adjust oil pump setting.

Service: For repairs beyond basic maintenance, take to authorized STIHL dealer.

Support: 1-800-467-8445; www.stihlusa.com