Murray 866086-00 Lawn Mower Manual

The Murray 866086-00 is a walk-behind, gas-powered lawn mower featuring a Briggs & Stratton engine, 21-inch steel cutting deck, single-lever height adjustment (6 positions), 2-in-1 side discharge/mulching capability, rear bagger, easy-start system, and durable steel construction. Below are key sections for safety, features, assembly, operation, maintenance, troubleshooting, and specifications.

1. Features at a Glance 2. Assembly Instructions 3. Safety Precautions 4. Specifications 5. Controls and Operation 6. Cutting Height Adjustment 7. Maintenance Schedule 8. Engine Care 9. Storage & Winterization 10. Warranty Information 11. Troubleshooting

Features at a Glance

Key components: Briggs & Stratton engine, 21-inch steel deck, height adjustment lever, rear grass bag, mulching plug, discharge chute, recoil starter, and fuel tank.

FeatureDescription
EngineBriggs & Stratton 125cc gas engine with easy-start technology
Cutting Width21-inch steel cutting deck
Cutting Options2-in-1: Side discharge or mulching (plug included)
Height AdjustmentSingle-lever, 6 positions (1.5" to 3.75")
Grass BagRear-mounted, 2.1 bushel capacity
Drive SystemPush-powered (non-self-propelled)
StarterRecoil pull-start mechanism
Fuel Tank0.5-gallon capacity
Wheels8-inch rear, 7-inch front plastic wheels
Deck MaterialRust-resistant painted steel

Assembly Instructions

Unpack and inspect all parts. Assembly requires basic tools (included).

  1. Attach handle: Align lower handle with deck brackets, secure with bolts and wing nuts.
  2. Install upper handle: Connect to lower handle, tighten knobs.
  3. Attach grass bag: Hook bag frame onto rear deck brackets.
  4. Install discharge chute: Slide into side discharge opening, secure with pin.
  5. Add mulching plug (if desired): Insert into deck opening when mulching.
  6. Check wheels: Ensure all wheels are securely fastened and rotate freely.
  7. Add engine oil and gasoline: Follow engine manual for type and quantity.

WARNING! Do not attempt to start engine before adding oil and fuel. Keep hands clear of cutting blade during assembly.

Safety Precautions

Always operate mower with caution to prevent injury.

  1. Read manual completely before use.
  2. Clear mowing area of stones, sticks, and debris.
  3. Wear sturdy shoes, eye protection, and long pants.
  4. Do not mow wet grass or in rain.
  5. Never allow children or pets near mower during operation.
  6. Disconnect spark plug wire before performing maintenance.
  7. Always push mower; never pull.
  8. Use both hands on handle; walk, never run.

CAUTION! The blade rotates at high speed. Keep hands and feet away from deck at all times.

Specifications

Controls and Operation

Handle includes recoil starter grip, operator presence control (bail), and height adjustment lever.

Starting: 1. Check oil and fuel. 2. Prime engine (if equipped). 3. Set throttle to FAST. 4. Pull recoil starter firmly.

Stopping: Release operator presence control (bail) to stop blade. Move throttle to STOP to stop engine.

Mowing: Engage bail to start blade, walk at steady pace, overlap passes slightly for even cut.

Cutting Height Adjustment

Single lever adjusts all four wheels simultaneously.

  1. Stop engine and wait for blade to stop completely.
  2. Pull height adjustment lever outward.
  3. Move lever to desired position (1-6, lowest to highest).
  4. Release lever to lock into place.
  5. Test by pushing mower to ensure all wheels are at same height.

Tip: For first mow of season, set to highest setting, then gradually lower.

Maintenance Schedule

IntervalTask
Before each useCheck oil level, inspect blade for damage, clear deck of debris
Every 25 hoursChange engine oil (or annually)
Every seasonReplace air filter, spark plug
As neededSharpen or replace blade, check tire pressure
After each useClean underside of deck, wipe down mower

WARNING! Always disconnect spark plug wire before performing any maintenance.

Engine Care

Refer to Briggs & Stratton manual for detailed engine maintenance.

  1. Oil: Check before each use. Change every 25 hours or annually. Use SAE 30 detergent oil.
  2. Air Filter: Clean foam pre-cleaner every 25 hours. Replace paper filter annually.
  3. Spark Plug: Replace annually. Gap: 0.030 inches.
  4. Fuel: Use fresh unleaded gasoline (87 octane min). Add fuel stabilizer for storage.
  5. Carburetor: May require adjustment if engine runs poorly.

Storage & Winterization

Prepare mower for off-season storage to prevent damage.

  1. Run engine to warm oil, then drain and refill with fresh oil.
  2. Add fuel stabilizer to tank, run engine 5 minutes to circulate.
  3. Disconnect spark plug wire and remove spark plug.
  4. Add 1 oz of oil through spark plug hole, pull starter slowly to coat cylinder, reinstall plug.
  5. Clean entire mower, especially underside of deck.
  6. Sharpen blade or replace if damaged.
  7. Store in dry, covered area.

CAUTION! Never store mower with fuel in tank indoors or near open flame.

Warranty Information

Murray 866086-00 comes with a 2-year limited warranty covering defects in materials and workmanship under normal residential use. Warranty does not cover wear items (blade, belts, etc.), damage from misuse, lack of maintenance, or commercial use. To make a warranty claim, contact Murray customer service at 1-800-269-6215 or visit www.murray.com. Keep original receipt as proof of purchase.

Troubleshooting

SymptomPossible CauseCorrective Action
Engine won't startNo fuel, old gas, clogged filter, bad spark plugCheck fuel; use fresh gas; clean/replace air filter; check spark plug.
Engine runs poorlyDirty air filter, old gas, clogged carburetorClean/replace air filter; drain old gas; clean carburetor.
Uneven cuttingDull blade, uneven tire pressure, deck cloggedSharpen/replace blade; check tire pressure; clean deck.
Excessive vibrationLoose blade, bent blade, debris in deckTighten blade bolt; replace bent blade; clean deck.
Grass not dischargingWet grass, deck clogged, engine speed too lowMow when dry; clean deck; run engine at FAST setting.
Wheels not turning freelyDebris in axles, over-tightened nutsClean axles; adjust wheel nuts.

Service: For engine issues, contact Briggs & Stratton at 1-800-233-3723. For mower issues, contact Murray at 1-800-269-6215 or visit www.murray.com.

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