stihl ms 260 workshop manual

The STIHL MS 260 is a professional-grade chainsaw featuring a high-performance engine, anti-vibration system, Quickstop® inertia chain brake, STIHL Ematic™ lubrication system, and a decompression valve for easier starting. This workshop manual provides detailed instructions for maintenance, repair, troubleshooting, and specifications. Below are key sections covering safety, technical data, maintenance procedures, engine service, fuel system, ignition system, and troubleshooting.

1. Features at a Glance 2. Safety Information 3. Technical Specifications 4. Maintenance Schedule 5. Engine Service 6. Fuel System 7. Ignition System 8. Chain & Bar 9. Troubleshooting 10. Parts Diagram 11. Warranty & Support

Features at a Glance

Key components: Engine cylinder, carburetor, air filter, spark plug, chain brake, oil pump, anti-vibration system, and decompression valve.

Feature	Description
Engine Displacement	50.2 cc
Power Output	3.0 bhp (2.2 kW)
Fuel Tank Capacity	0.53 US pt (0.25 l)
Oil Tank Capacity	0.32 US pt (0.15 l)
Chain Pitch	3/8" PMM or .325"
Weight (powerhead)	10.8 lbs (4.9 kg)
Ignition System	Electronic, capacitor discharge
Anti-Vibration System	Spring-mounted handles
Chain Brake	Quickstop® inertia activated
Decompression Valve	Reduces starting effort

Safety Information

Always wear protective equipment: helmet, goggles, gloves, chainsaw chaps, and hearing protection.

Pre-Operation Check: Inspect chain tension, sharpness, and lubrication before each use.
Chain Brake Test: Verify Quickstop® function regularly.
Fuel Handling: Use fresh fuel mix (50:1 STIHL HP Ultra oil with 89 octane gasoline).
Working Area: Ensure clear escape path, secure footing, and no bystanders.

WARNING! Never operate a chainsaw with damaged or missing safety features. Keep hands away from moving chain.

Technical Specifications

Engine Type: Single cylinder, two-stroke, air-cooled.
Bore x Stroke: 44 mm x 33 mm.
Idle Speed: 2,800 RPM (factory set).
Maximum Power Speed: 9,500 RPM.
Spark Plug: Bosch WSR 6 F or NGK BPMR 7A, gap 0.020" (0.5 mm).
Carburetor: Zama C1Q-S series, adjustable H, L, LA screws.
Fuel/Oil Ratio: 50:1 (STIHL HP Ultra).
Chain Oil: STIHL HP or equivalent biodegradable chain oil.
Sound Pressure Level: 106 dB(A).
Vibration Level: Front handle 4.2 m/s², rear handle 2.8 m/s².

Maintenance Schedule

Access maintenance points via removal of covers and air filter. Daily: Clean air filter, check chain tension and sharpness. Weekly: Clean cooling fins, check spark plug. Monthly: Clean fuel filter, inspect anti-vibration elements. Annually: Replace fuel line, inspect clutch and sprocket.

Remote: Not applicable. Use appropriate STIHL tools (spark plug wrench, combination wrench, screwdrivers).

Engine: Check compression (minimum 120 psi). Fuel System: Clean carburetor, replace filters. Ignition: Check coil air gap (0.010" / 0.25 mm). Chain/Bar: File cutters to 30°, depth gauges to 0.025" (0.65 mm).

Engine Service

Cylinder & Piston: Inspress for scoring. Remove muffler to view piston through exhaust port.

Disconnect spark plug wire.
Remove engine covers and air filter assembly.
Remove carburetor and intake manifold.
Remove cylinder bolts, lift cylinder.
Inspect piston rings, cylinder walls.
Reassemble with new gaskets; torque cylinder bolts to 10 Nm (88 in-lb).

Tip: Clean carbon from exhaust port and muffler screen regularly.

Fuel System

Includes fuel tank, filter, lines, and carburetor.

Drain fuel tank.
Remove fuel filter through filler neck with wire hook.
Replace fuel lines if cracked or hardened.
Carburetor Adjustment: Initial settings: H=1 turn open, L=1 turn open, LA=1 turn open. Fine-tune at operating temperature.
Pressure/Vacuum Test: Check for leaks with pressure pump (7 psi hold).

WARNING! Use only fresh fuel mix. Stale fuel causes starting and performance issues.

Ignition System

Electronic ignition module, spark plug, stop switch, and wiring.

Spark Test: Remove plug, ground to cylinder, pull starter – look for strong blue spark.
Coil Air Gap: Set to 0.010" (0.25 mm) with business card.
Module Test: Resistance primary 0.5-2.0 Ω, secondary 8-15 kΩ.
Stop Switch: Continuity check – open when switch off.

CAUTION! Never pull starter with spark plug disconnected and wire ungrounded – can damage ignition module.

Chain & Bar

Maintain sharp cutters, proper depth gauge height, and adequate lubrication.

Chain Tension: Adjust so chain snaps back when lifted from bar. Sharpening: File at 30° angle, maintain cutter length equality. Bar Maintenance: Clean groove, flip weekly for even wear. Oil Flow Check: Run at high idle, hold tip over clean surface – oil streak should appear.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No spark, fuel, or compression	Check spark, fuel freshness, compression (min 120 psi).
Engine runs poorly	Clogged air filter, carb adjustment	Clean filter; adjust H and L screws.
Chain won't turn	Clutch worn, sprocket damaged	Inspect clutch shoes and drum; replace if worn.
Excessive vibration	AV mounts damaged, unbalanced chain	Replace anti-vibration buffers; balance chain.
Oil not flowing	Clogged oil passages, pump faulty	Clean oil ports; test pump output.

Reset: Carburetor to factory settings if over-adjusted.

Service: Authorized STIHL servicing dealer only for warranty repairs.

Parts Diagram

Refer to official STIHL MS 260 IPL (Illustrated Parts List) for part numbers and exploded views. Common replacement parts: Fuel filter (1130 141 1600), Air filter (1128 140 0600), Spark plug (WSR 6 F), Carburetor kit (1130 007 1060), Chain brake band (1128 650 7701).

Warranty & Support

STIHL Limited Warranty: 1 year commercial, 2 year residential. Proof of purchase required. Copyright © STIHL Incorporated. All specifications subject to change. For technical support, contact an authorized STIHL dealer or visit www.stihlusa.com.