Craftsman M110 Lawn Mower Engine Manual

The Craftsman M110 is a 140cc Briggs & Stratton-powered push lawn mower featuring a 21-inch steel deck, 3-in-1 capability (mulch/bag/side-discharge), single-lever height adjustment, and easy-start technology. This manual covers safety, operation, maintenance, troubleshooting, and specifications for the M110 model. Always read and understand all instructions before use.

1. Safety Information 2. Features & Components 3. Assembly & Setup 4. Operation Instructions 5. Engine Specifications 6. Controls & Adjustments 7. Maintenance Schedule 8. Storage & Winterization 9. Troubleshooting Guide 10. Warranty Information

Safety Information

Read all safety warnings before operating. Key hazards include rotating blade, fuel, and hot surfaces.

Symbol	Warning	Precaution
⚠️	Rotating Blade	Keep hands and feet away from deck. Disconnect spark plug before servicing.
🔥	Fuel Safety	Refuel outdoors, engine off and cool. Use approved container.
👂	Hearing Protection	Wear ear protection during extended use.
👁️	Eye Protection	Wear safety glasses to guard against debris.
🚫	Children & Pets	Keep area clear during operation. Do not allow riders.

Features & Components

Key components: 140cc Briggs & Stratton engine, 21-inch steel deck, rear bag, mulch plug, height adjustment lever, recoil starter, fuel tank, oil fill, air filter, spark plug.

Engine: 140cc OHV Briggs & Stratton, 5500 max RPM.
Deck: 21-inch stamped steel, 3-in-1 design.
Cutting Height: 6 positions (1.25-3.75 inches).
Starting: Recoil pull-start with primer bulb.
Wheels: 8-inch rear, 7-inch front.
Bag Capacity: 2.1 bushels (side bagger).

Assembly & Setup

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

Attach handle: Secure upper and lower sections with provided bolts.
Install wheels: Insert axle pins; secure with retainer clips.
Attach bag: Hook bag frame onto deck rear; secure with brackets.
Add oil: Use SAE 30 (approx. 20 oz) – check dipstick.
Add fuel: Use fresh unleaded gasoline (max 87 octane).
Check blade: Ensure sharp and secure (torque: 45-55 ft-lbs).

WARNING! Do not start engine without oil. Ensure all fasteners are tight.

Operation Instructions

Starting, mowing, and stopping procedures.

Pre-start: Check oil and fuel. Set height lever. Engage blade control.
Starting: Prime 3 times (cold engine). Pull recoil steadily.
Mowing: Push at steady pace; overlap rows for even cut.
Stopping: Release blade control; wait for blade to stop. Turn engine off.
Bagging/Mulching: Install bag or mulch plug per desired function.

Tip: Mow when grass is dry for best results. Avoid mowing in reverse.

Engine Specifications

Engine Model: Briggs & Stratton 550e Series.
Displacement: 140cc (8.5 cubic inches).
Power: 3.5 HP @ 3600 RPM.
Fuel Type: Unleaded gasoline (87 octane min).
Oil Type: SAE 30 (above 40°F) or 10W-30 (variable temp).
Oil Capacity: 20 oz (0.6 L).
Air Filter: Dual-element foam and paper.
Spark Plug: Champion RC12YC (gap 0.030 inch).

Controls & Adjustments

Primary controls: Blade engagement lever, throttle control, height adjustment, primer bulb, recoil starter.

Height Adjustment: Single lever adjusts all four wheels simultaneously (1.25" to 3.75").

Blade Engagement: Pull lever against handle to engage; release to disengage.

Throttle Control: Set to FAST for mowing, SLOW for idle, STOP to shut off.

Choke: Use for cold starts (lever near throttle).

Maintenance Schedule

Regular maintenance ensures long engine life and optimal performance.

Interval	Task	Details
Before each use	Check oil level	Maintain full mark on dipstick.
Every 5 hours	Clean deck	Remove grass buildup underneath.
Every 25 hours	Change oil	Drain warm oil; refill with SAE 30.
Every season	Replace air filter	Clean foam pre-filter; replace paper if dirty.
Every season	Sharpen blade	Balance after sharpening.
Every 100 hours	Replace spark plug	Gap to 0.030 inch.

Storage & Winterization

Proper storage prevents fuel system issues and corrosion.

Drain or stabilize fuel: Run engine dry or add fuel stabilizer.
Change oil: Replace with fresh oil before storage.
Clean deck: Remove all grass and debris.
Remove spark plug: Add 1 tbsp oil into cylinder; pull recoil slowly to coat.
Store indoors: Keep in dry, covered area.

CAUTION! Never store with fuel in tank untreated. Disconnect spark plug wire.

Troubleshooting Guide

Problem	Possible Cause	Solution
Engine won't start	No fuel, old gas, clogged filter	Check fuel; use fresh gas; clean/replace filter.
Engine runs poorly	Dirty air filter, bad spark plug	Clean air filter; replace spark plug.
Uneven cut	Dull blade, uneven deck	Sharpen blade; level deck (check tire pressure).
Excessive vibration	Bent blade, loose parts	Inspect blade; tighten all bolts.
Bag not filling	Wet grass, clogged chute	Mow when dry; clear chute of debris.
Oil leak	Loose drain plug, overfilled	Tighten plug; drain excess oil.

Warranty Information

Craftsman M110 includes a 2-year limited warranty covering defects in materials/workmanship. Proof of purchase required. Warranty does not cover normal wear, misuse, or lack of maintenance. For warranty service, contact Craftsman Customer Support at 1-888-331-4569 or visit www.craftsman.com.

Serial Number Location: Stamped on engine housing and deck frame. Record for reference.