John Deere CS81 Chainsaw Owner's Manual

The John Deere CS81 is a professional-grade chainsaw designed for demanding cutting tasks. It features an 81cc engine, a high-performance cutting system, advanced safety features, and ergonomic design for operator comfort. This manual covers essential safety instructions, assembly, operation, maintenance, troubleshooting, and specifications to ensure safe and efficient use. Always read and understand this manual completely before operating the chainsaw.

1. Safety Information 2. Features & Components 3. Assembly & Preparation 4. Specifications 5. Controls & Operation 6. Chain & Bar Maintenance 7. Engine Maintenance 8. Fuel & Lubrication 9. Storage 10. Troubleshooting 11. Warranty & Support

Safety Information

Operating a chainsaw involves serious risks. Failure to follow safety instructions can result in severe injury or death.

Hazard	Precaution
Kickback	Always use a low-kickback chain; hold saw firmly with both hands; do not cut with tip.
Contact with chain	Always engage chain brake when not cutting; wear protective chaps and gloves.
Noise & Vibration	Wear hearing protection; take regular breaks to reduce fatigue.
Falling branches	Clear work area; be aware of your surroundings; wear a hard hat.
Fuel hazards	Refuel in well-ventilated area with engine off and cool; no smoking.
Electrical hazards	Keep saw away from power lines; assume all lines are energized.
Exhaust fumes	Operate only in well-ventilated areas to prevent carbon monoxide poisoning.
Hot surfaces	Avoid contact with muffler and cylinder during/after operation.

WARNING! Never operate when tired, ill, or under the influence of drugs/alcohol. Always use personal protective equipment (PPE): helmet, eye/ear protection, gloves, chainsaw chaps, and steel-toe boots.

Features & Components

Key components of the John Deere CS81 chainsaw.

Component	Description
Engine	81cc 2-stroke gasoline engine with electronic ignition
Bar Length	20-inch standard guide bar (other lengths available)
Chain	Low-kickback, chipper-type cutting chain
Chain Brake	Inertia-activated front hand guard/chain brake
Throttle Trigger	With safety interlock to prevent accidental engagement
Master Control Lever	Combines choke, stop, and run functions
Anti-Vibration System	Reduces operator fatigue during extended use
Air Filtration	Heavy-duty air filter with easy-access cover
Fuel & Oil Caps	Large, easy-to-grip caps with tethers
Decompression Valve	Easier starting by reducing cylinder pressure

Assembly & Preparation

Assembling your chainsaw from the box.

Unpacking: Remove all packaging materials. Check contents: chainsaw, guide bar, chain, scrench tool, owner's manual.
Attach Guide Bar & Chain: Loosen bar nuts. Place bar over studs. Fit chain over sprocket and onto bar groove, ensuring cutting teeth face forward on top. Tighten bar nuts finger-tight. Adjust chain tension (see section 6). Final-tighten bar nuts.
Add Fluids: Fill fuel tank with fresh gasoline/oil mix (50:1 high-quality 2-cycle oil). Fill bar & chain oil reservoir with specified bar oil.
Pre-Start Check: Ensure chain brake is disengaged. Check all fasteners for tightness. Inspect chain for proper tension and sharpness.

CAUTION! Do not attempt to start the saw until assembly is complete and you have read the Safety Information.

Specifications

Engine Displacement: 81 cc
Engine Type: 2-stroke, air-cooled, single cylinder
Fuel/Oil Mix: 50:1 (Unleaded gasoline with JASO FD or ISO-L-EGD rated 2-cycle oil)
Fuel Tank Capacity: 24.3 fl oz (720 ml)
Oil Tank Capacity: 12.2 fl oz (360 ml)
Recommended Bar Lengths: 18" to 24"
Chain Pitch/Gauge: .325" pitch, .063" gauge (standard)
Idle Speed: 2,800 RPM
Maximum Power Speed: 9,500 RPM
Sound Pressure Level: 112 dB(A) (Wear hearing protection!)
Vibration Level: Front/Rear handles: 4.5/2.5 m/s²
Dry Weight (w/o bar & chain): 14.3 lbs (6.5 kg)

Controls & Operation

Understanding and using the controls safely.

Controls: Master Control Lever (Choke/Stop/Run), Throttle Trigger with interlock, Chain Brake/Hand Guard, Throttle Lockout, Decompression Valve, Primer Bulb (if equipped).

Starting Procedure (Cold Engine):

Place saw on firm, flat ground. Engage chain brake.
Press decompression valve (if equipped).
Move Master Control to CHOKE position. Pump primer bulb 5-6 times (if equipped).
Hold front handle with left hand, place right foot in rear handle. Pull starter rope sharply until engine 'pops'.
Move Master Control to RUN position. Pull starter rope again to start.
Allow engine to warm up at idle for 30 seconds. Disengage chain brake before cutting.

Basic Cutting: Use a firm, two-handed grip. Let the saw do the work; do not force it. Be aware of pinch points, kickback zones, and falling material.

Stopping: Release throttle, allow engine to idle. Move Master Control to STOP position.

Chain & Bar Maintenance

Proper chain and bar care is critical for performance and safety.

Chain Tension: Check frequently when new. Chain should be snug against bar but pull freely by hand. Adjust via side tensioner: Loosen bar nuts, turn adjustment screw, retighten bar nuts. A loose chain can derail; an overtightened chain can damage the bar and engine.
Sharpening: Use a round file matching chain pitch (e.g., 5/32" for .325" pitch). Maintain correct filing angle (typically 30°). File all cutters to equal length. File depth gauges (rakers) with a flat file and gauge.
Bar Maintenance: Clean bar groove regularly. Flip bar weekly for even wear. Dress bar rails with a flat file if burred.
Sprocket Inspection: Check drive sprocket for wear. Replace if teeth are hooked or excessively worn.

WARNING! Always wear heavy gloves when handling the chain. Ensure the engine is off and the chain is cool.

Engine Maintenance

Routine engine maintenance ensures longevity and reliability.

Maintenance Item	Interval	Procedure
Air Filter	Daily or as needed	Clean with soap/water or compressed air. Replace if damaged.
Spark Plug	Every 25 hours	Clean electrodes, check gap (0.020" / 0.5mm). Replace annually.
Spark Arrestor Screen (Muffler)	Every 25 hours	Remove and clean carbon deposits.
Fuel Filter	Every 50 hours or season	Replace in-tank fuel filter.
Cylinder Fins	Weekly	Clean debris to prevent overheating.
Carburetor Adjustment	As required	Adjust idle (L) and high-speed (H) screws only with proper tool and knowledge.

CAUTION! All maintenance must be performed with the engine off and cool. Disconnect the spark plug wire for safety.

Fuel & Lubrication

Using the correct fuels and lubricants is essential.

Fuel Mix: Use 89 octane or higher unleaded gasoline. Mix with a high-quality 2-cycle engine oil certified JASO FD or ISO-L-EGD at a 50:1 ratio. Shake container well before filling. Never use automotive oil or old/stale fuel.
Bar & Chain Oil: Use a quality bar & chain oil with tackifiers. In cold weather (< 40°F / 4°C), use a winter-grade oil. Check oil flow frequently; adjust oiler if equipped.
Gearbox Lubrication (if equipped): Some models require periodic greasing of the clutch bearing. Consult your specific manual.

Storage Tip: For storage over 30 days, drain all fuel from the tank and run the engine until it stops to prevent gum formation in the carburetor.

Storage

Proper storage protects your investment.

Short-term (under 30 days): Clean saw thoroughly. Top up fuel tank with fresh mix to prevent condensation. Store in a dry, locked location out of reach of children.
Long-term (over 30 days):
- Drain fuel tank and run engine until it stops to clear carburetor.
- Drain bar & chain oil tank.
- Remove chain, clean it and the bar, coat with oil and store separately.
- Clean entire saw. Remove spark plug, add a teaspoon of engine oil into cylinder, pull starter slowly to coat, reinstall plug.
- Store in a cool, dry place.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine will not start	No spark, flooded, old fuel, master control wrong position	Check spark plug; move control to RUN; use fresh fuel; wait if flooded.
Engine starts then dies	Clogged fuel filter, dirty air filter, carburetor adjustment	Replace fuel filter; clean air filter; check carburetor settings.
Engine lacks power	Dirty air filter, clogged spark arrestor, dull chain	Clean air filter and spark arrestor; sharpen chain.
Chain does not turn	Chain brake engaged, clutch worn, sprocket damaged	Disengage chain brake; inspect clutch and sprocket.
Excessive vibration	Loose components, unbalanced chain, damaged bar	Tighten all fasteners; sharpen chain evenly; inspect/replace bar.
Chain throws oil	Oil port clogged, wrong oil viscosity, overfilled tank	Clean oil ports; use correct oil; check tank level.
Chain comes off bar	Loose chain, worn bar, damaged drive links	Adjust tension; inspect bar for wear; replace damaged chain.

Note: For complex repairs, contact an authorized John Deere service dealer.

Warranty & Support

John Deere CS81 chainsaws are backed by a limited warranty. Proof of purchase is required.

Warranty Period: Consult your local John Deere dealer for specific warranty terms, which may vary by region.
What is Covered: Defects in materials or workmanship under normal use.
What is Not Covered: Damage from misuse, neglect, improper maintenance, unauthorized modifications, or use of incorrect fuels/lubricants.
Support: For technical assistance, parts, or to locate a dealer:
- Visit: www.JohnDeere.com
- Contact your local authorized John Deere dealer.
- Refer to the contact information provided with your purchase.

Always use genuine John Deere replacement parts to maintain performance and safety.