The Craftsman M310 is a 21-inch self-propelled gas lawn mower featuring a 140cc Briggs & Stratton engine, 3-in-1 capability (mulch/bag/side discharge), single-lever height adjustment, and a durable steel deck. This parts manual provides detailed diagrams, part numbers, and ordering information for maintenance, repair, and replacement of components. Below are key sections covering identification, engine parts, deck assembly, drive system, controls, and troubleshooting.
Locate model number on product label (example: 917.388XXX). Key specs: 21-inch steel deck, 140cc OHV engine, 2.5 bushel bag capacity, 6-position cutting height (1.25-3.75 inches), self-propelled rear-wheel drive.
| Feature | Description |
|---|---|
| Model Series | M310 (typically part of Craftsman 300 series) |
| Engine | Briggs & Stratton 140cc, 450E series, OHV |
| Cutting Width | 21 inches |
| Deck Material | Powder-coated steel |
| Drive System | Single-speed self-propelled, rear-wheel drive |
| Cutting Height Adjust | Single lever, 6 positions |
| Fuel Tank Capacity | Approx. 1.0 quart |
| Oil Capacity | 20 oz (0.6L), SAE 30 detergent oil |
| Weight | Approx. 75 lbs |
| Mulching Capability | Yes (with mulch plug installed) |
Briggs & Stratton 140cc engine parts list. Always disconnect spark plug before servicing.
WARNING! Gasoline is flammable. Allow engine to cool before servicing fuel system.
21-inch steel deck parts. Remove deck by disconnecting drive cable, height adjust linkage, and blade bolt.
CAUTION! Wear gloves when handling blades. Ensure blade is balanced after installation.
Self-propelled drive system components. The M310 uses a belt-driven transmission to rear wheels.
Upper handle assembly and control components. Handle folds for storage.
Handle Assembly: Part # 532141728 - Complete upper handle with grips.
Control Cables: Throttle cable (Part # 532142031), drive cable (Part # 532140956).
Safety Key: Part # 532142334 - Ignition interlock blade control lever.
Starter Handle: Part # 532142637 - Recoil starter grip.
Bag Indicator Flag: Part # 532142938 - Signals when bag is full.
Wheel and axle parts. 8-inch rear wheels, 7-inch front wheels.
Front Wheels: Part # 532143241 - 7-inch plastic with bushings.
Rear Wheels: Part # 532143544 - 8-inch plastic with drive hub.
Axle Bolts & Nuts: Part # 876543 (rear), Part # 876544 (front).
Tip: Lubricate axle sleeves annually with light oil.
3-in-1 conversion parts. Bagging system includes bag, frame, and chute.
WARNING! Always install bag or mulch plug when operating. Never operate without proper discharge control.
Regular maintenance ensures optimal performance and longevity.
| Interval | Task | Part # (if needed) |
|---|---|---|
| Before each use | Check oil level, inspect blade | N/A |
| Every 25 hours | Change oil, replace air filter | 492932S (filter) |
| Every 50 hours | Replace spark plug, check drive belt | 591023 (plug) |
| Season end | Drain fuel, clean deck, sharpen blade | 532401214 (blade) |
| As needed | Lubricate wheels/axles, check cables | Light oil, 532142031 (cable) |
Always follow safety precautions to prevent injury.
CAUTION! Disconnect spark plug before any maintenance. Keep hands and feet away from moving parts. Do not mow on slopes greater than 15 degrees. Wear eye protection and sturdy footwear. Never remove safety devices or guards. Use only original Craftsman parts for repair.
Craftsman M310 parts are available through authorized dealers, Sears Parts Direct, and online retailers.
| Symptom | Possible Cause | Corrective Action / Part Needed |
|---|---|---|
| Engine won't start | Old fuel, clogged filter, bad spark plug | Drain fuel, replace filter (808656) and plug (591023). |
| Poor cut quality | Dull/bent blade, clogged deck | Sharpen or replace blade (532401214); clean deck. |
| Self-propel not working | Worn drive belt, loose cable | Replace belt (532140854); adjust cable (532140956). |
| Vibration/excessive noise | Loose blade, unbalanced blade, damaged adapter | Tighten blade bolt; replace adapter (732-04154). |
| Oil leak | Loose drain plug, worn gasket | Tighten plug; replace plug/gasket (691068). |
| Wheels not turning freely | Debris in axle, lack of lubrication | Clean axle; lubricate with light oil. |
Reset: For safety interlock issues, ensure all controls are in proper positions.
Service: For technical support, call 1-888-331-4569 or visit www.craftsman.com.