Craftsman M125 Lawn Mower Manual

The Craftsman M125 is a 21-inch push lawn mower featuring a 140cc Briggs & Stratton engine, 3-in-1 cutting system (mulch, bag, side discharge), single-lever height adjustment (6 positions from 1.25" to 3.75"), durable steel deck, easy-start system, and rear-wheel drive. This manual covers safety, assembly, operation, maintenance, troubleshooting, and specifications for optimal performance and longevity.

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

Features at a Glance

Key components: 140cc Briggs & Stratton engine, 21-inch steel cutting deck, 3-in-1 discharge system, single-lever height adjustment, rear-wheel drive, foldable handle, and easy-start system.

Feature	Description
Engine	140cc Briggs & Stratton 450E Series, OHV
Cutting Width	21 inches
Cutting System	3-in-1 (Mulch, Bag, Side Discharge)
Height Adjustment	Single lever, 6 positions (1.25" to 3.75")
Drive System	Rear-wheel drive
Deck Material	Durable steel
Start Type	Recoil start with easy-start system
Wheels	8-inch rear, 7-inch front
Fuel Tank Capacity	0.95 gallons
Oil Capacity	20 oz (SAE 30 recommended)

Assembly Instructions

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

Attach handle: Insert lower handle into deck brackets, secure with bolts and wing nuts.
Install wheels: Slide axles through deck, secure wheels with washers and retaining clips.
Attach discharge chute: Align with side discharge port, secure with provided pin.
Install grass bag: Hook bag frame onto rear deck brackets.
Add oil and fuel: Fill engine with SAE 30 oil (20 oz) and unleaded gasoline (87 octane minimum).

WARNING! Wear gloves during assembly. Ensure all fasteners are tight before operation.

First-Time Setup

Complete assembly, then prepare for first use.

Check oil level: Ensure oil is at full mark on dipstick.
Add fuel: Use fresh unleaded gasoline; avoid ethanol blends above 10%.
Adjust cutting height: Set lever to desired position (recommend 2.5" for first mow).
Select discharge mode: Install mulch plug, bag, or side chute as needed.
Start engine: Set throttle to fast, pull recoil starter firmly.

CAUTION! Operate outdoors only. Clear mowing area of debris before starting.

Specifications

Model: Craftsman M125
Engine: 140cc Briggs & Stratton 450E Series, OHV
Cutting Width: 21 inches
Cutting Height Range: 1.25" to 3.75" (6 positions)
Deck Material: 20-gauge steel
Drive System: Rear-wheel drive
Wheels: 8" rear, 7" front
Fuel Capacity: 0.95 gallons
Oil Type: SAE 30 (20 oz capacity)
Weight: 65 lbs (approx.)
Warranty: 2-year limited

Controls and Operation

Handle controls: Drive control lever, throttle control, recoil starter, height adjustment lever.

Operation Steps:

Check area: Remove stones, toys, and debris.
Set height: Adjust lever to desired cutting height.
Start engine: Set throttle to fast, pull recoil starter.
Engage drive: Press drive control lever against handle to move forward.
Mow in overlapping passes: For even cut, overlap each pass by 2-3 inches.

Safety Controls: Blade control lever (must be held to keep blade spinning), engine stop switch.

Cutting System Setup

3-in-1 system allows mulching, bagging, or side discharge.

Mulching: Install mulch plug in discharge chute. Cuts clippings finely and returns to lawn.
Bagging: Attach grass bag to rear brackets. Collects clippings for disposal.
Side Discharge: Install discharge chute. Ejects clippings to side (right).

Tip: For best mulching, mow when grass is dry and not too tall. Empty bag when half full.

Maintenance Schedule

Interval	Task
Before each use	Check oil level, inspect blade for damage, clear deck of debris
Every 25 hours	Change engine oil, check air filter, inspect spark plug
Every season	Sharpen or replace blade, lubricate wheels and height adjuster
Storage	Drain fuel or add stabilizer, clean deck, store in dry place

Blade Sharpening: Disconnect spark plug, remove blade, sharpen at 30-degree angle, balance before reinstalling.

Safety Features

Blade control lever: Blade stops within 3 seconds of release. Engine stop switch: Immediate engine shutdown. Safety labels: Read and follow all warnings on mower.

Safe Operation Rules:

Wear sturdy shoes and eye protection.
Do not mow wet grass.
Keep hands and feet away from moving parts.
Turn off engine before clearing blockages or adjusting height.
Do not allow children to operate.

Storage & Winterization

Prepare mower for off-season storage.

Clean deck: Remove grass clippings and debris.
Drain fuel: Run engine until tank is empty, or add fuel stabilizer.
Change oil: Replace with fresh SAE 30 oil.
Remove spark plug: Add teaspoon of oil to cylinder, pull starter slowly to coat.
Store indoors: Keep in dry, covered area; fold handle to save space.

CAUTION! Never store with fuel in tank over 30 days without stabilizer.

Warranty Information

Craftsman M125 includes a 2-year limited warranty covering defects in materials and workmanship. Warranty does not cover normal wear, misuse, or lack of maintenance. For warranty service, contact Craftsman customer service at 1-888-331-4569 or visit www.craftsman.com. Keep original receipt as proof of purchase.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No fuel, old gas, clogged air filter	Add fresh fuel, clean/replace air filter, check spark plug.
Poor cutting performance	Dull blade, low engine speed	Sharpen/replace blade, set throttle to fast.
Vibration or shaking	Loose blade, bent blade, debris	Tighten blade bolt, replace bent blade, clean deck.
Wheels not turning	Drive cable loose, debris in drive	Adjust drive cable, clear obstructions.
Engine smokes	Overfilled oil, air filter dirty	Drain excess oil, clean air filter.

Service: For repairs, contact authorized Craftsman service center. Use only genuine Craftsman parts.

Support: 1-888-331-4569; www.craftsman.com