CRAFTSMAN M260 Service Manual
Overview and safety information
The Craftsman M260 service manual provides a comprehensive guide for diagnosing, maintaining, repairing, and rebuilding the M260 outdoor power equipment. This document is designed to help technicians understand the construction, operation, and service requirements of the machine, including recommended tools, torque specifications, lubrication points, and electrical connections. It outlines step-by-step procedures to safely disassemble and reassemble components, perform routine maintenance, and address common malfunctions. Readers can expect detailed illustrations and reference data that support accurate troubleshooting and reliable repairs, ensuring equipment uptime and extended service life when followed correctly. The manual emphasizes a methodical approach, using manufacturer-approved procedures to minimize wear and prevent damage to critical systems.
Safety is a central theme throughout the manual, with emphasis on recognizing potential hazards associated with gasoline-powered equipment, rotating blades, hot surfaces, and fuel handling. Proper PPE is described and recommended for various tasks, including eye protection, hearing protection, gloves, and protective clothing. The document also covers safe work practices such as securing the machine on a stable surface, disconnecting the spark plug before performing any maintenance, and ensuring the area is well-ventilated during fueling and testing. Environmental and fire-safety considerations are included, detailing proper fuel storage, spill containment, and the correct disposal of used oil and components. Adhering to these precautions reduces the risk of injury and equipment damage during service operations.
The manual includes a section on identification and model variations to help technicians verify compatibility and select appropriate parts. It explains how to locate model and serial numbers, inspect labeling for engine type and configuration, and differentiate between production runs or regional variants that may affect service procedures. Understanding model variations ensures that torque values, gasket and seal selections, and component fitment are correct for the specific machine. The section provides guidance on cross-referencing parts diagrams with actual components found on the unit and emphasizes careful documentation when ordering replacement parts. This information supports accurate maintenance planning and helps prevent errors that could compromise performance or safety.
The Craftsman M260 mower requires a core set of hand tools and basic power tools to perform routine maintenance effectively. A metric and standard combination wrench set, a set of screwdrivers (flat-blade and Phillips), needle-nose pliers, and a torque wrench are essential for removing covers, removing bolts, and securing fasteners to precise specifications. A set of socket wrenches, ratchets, and adapters, along with a magnetic pickup tool, helps locate dropped fasteners in tight spaces. For proper lubrication and fastener protection, include a brandspecific oil filter wrench, a small brush for dirt removal, and a judicious amount of dielectric grease or lubricant. Finally, a digital multimeter is useful for diagnosing electrical issues, testing battery health, and confirming continuity on essential circuits during routine inspections.
Specialized equipment and where to source parts play a critical role in sustaining the M260’s performance over time. A sturdy workbench with a bright, shadow-free work area assists in precise alignment and safe component handling. A torque screwdriver or calibrated torque wrench ensures fasteners are tightened to the manufacturer’s specifications, preventing over- or under-tightening. The mower’s fuel system may benefit from a fuel-capable canister for safely disposing of old fuel and a fuel line disconnect tool when servicing the carburetor. When sourcing parts, rely on authorized Craftsman distributors or reputable parts suppliers that offer OEM filters, gaskets, and drive belts. Keep a spare set of common consumables such as air filters, fuel filters, blades, and oil to minimize downtime between maintenance intervals. Documentation or a parts catalog from the manufacturer will help verify compatibility and part numbers before ordering.
Tool maintenance and calibration procedures are essential to ensure consistent performance and accurate diagnostics. After each maintenance session, clean all tools to remove dirt, grime, and fuel residue, and apply a light coat of oil to metal surfaces to prevent rust. Calibrate torque tools regularly by cross-checking with a known reference torque and recording the results to ensure ongoing accuracy. Inspect blades for nicks or wear and balance them as required to reduce vibration and improve cutting efficiency. Keep a dedicated storage bin or roll for tools to prevent loss and to maintain an organized workspace. Regularly inspect the carburetor and fuel system for signs of varnish or buildup, and replace gaskets or seals as necessary to prevent air leaks. Finally, document all maintenance activities with dates, parts used, and measured values to build a traceable service history that can inform future repairs and preventative actions.
Engine and fuel system maintenance
The M260 engine is designed to deliver reliable performance through a balance of airflow, combustion efficiency, and durable components. Begin with a thorough understanding of the engine’s operating principles: the crankcase houses the crankshaft and connecting rods, while the camshaft controls valve timing to ensure proper intake and exhaust cycles. Fuel is delivered through a pressurized system that mixes with air in the carburetor, creating a combustible mixture that powers the piston motion. Regular inspection of the spark plug, air filter, and fuel lines helps maintain optimal ignition timing and combustion efficiency, reducing wear and improving fuel economy. Always verify that the engine is cool before performing any maintenance to avoid burns and accidental fuel exposure.
To establish a baseline, perform a visual inspection for oil leaks, cracked hoses, and loose connections around the engine bay. Check the cooling system if applicable, including any shrouds or fins that aid in heat dissipation. Ensure that the air intake is free of debris, and that the muffler and exhaust path are unobstructed to prevent back pressure that can impair performance. Record any abnormal sounds or vibrations, as these can indicate worn bearings, a misadjusted carburetor, or intake leaks. Maintain clean, dry hands-on procedures and use proper personal protective equipment during all inspections.
Fuel system inspection and cleaning begins with assessing fuel quality and ensuring the fuel tank is free of water or sediment. Replace any deteriorated fuel caps seals to maintain proper vapor pressure and prevent contamination. Inspect fuel lines for cracks, stiffness, or deformation and replace compromised sections promptly. When inspecting the carburetor and lines, look for signs of fuel leaks, tacky residues, or a stale fuel smell, which can indicate an aging system. After cleaning, run the engine to observe fuel delivery characteristics and verify that there are no leaks at fittings or hose clamps. Document findings and follow manufacturer recommendations for service intervals to keep the system within specification.
Carburetor maintenance and adjustment requires careful attention to idle speed, mixture settings, and choke operation. Begin by removing the carburetor top or air intake assembly as dictated by the model, keeping track of all screws and gaskets. Clean all passages with a non-residual carburetor cleaner, taking care not to damage soft seals or diaphragms. When reinstalling, recheck the intake manifold and gasket surface for flatness to prevent air leaks. Adjust idle speed to the recommended RPM using the appropriate linkage or screws, and verify that the engine returns to a stable idle after a brief blip of throttle. If symptoms persist, perform a calibrated fuel mixture adjustment in small increments, testing the engine under load to confirm performance without flooding the combustion chamber. Proper carburetor maintenance reduces fuel consumption and improves throttle response across operating conditions.
Fuel line and filter replacement should be performed with the fuel system depressurized and the engine cool. Inspect the entire length of fuel lines for delamination, cracking, or stiffening, and replace any suspect sections with OEM-compatible parts. Install new fuel filters where specified, ensuring the flow direction is correct and that fittings are snug without over-tightening. When routing new lines, avoid sharp bends and ensure clearance from hot surfaces, moving parts, and potential pinch points. After replacement, bleed the system if required and check for leaks at every connection using a safe soap solution or industry-approved leak detector. Perform a test run to confirm steady fuel delivery and responsive throttle action, recording any irregularities for future maintenance planning.
Lubrication is essential to keep the CRAFTSMAN M260’s engine running smoothly and to extend its service life. Begin with a clear inspection of the lubrication chart and intervals to determine how often oil changes and filter replacements are required under typical operating conditions. The engine should be checked for oil level at a consistent point in the maintenance cycle, ideally when the engine is cool and on a level surface. Use a clean, quality oil and a new filter if applicable, ensuring that the oil reaches the full mark on the dipstick after a short restart and rechecking. Regular lubrication also includes inspecting linkage and bearings for signs of seizing or abnormal wear, which can indicate lubrication gaps or contamination. Document all service activities so future maintenance can be accurately scheduled and tracked.
Oil type specifications for the M260 must align with the manufacturer’s recommendations to guarantee optimal lubrication and cooling performance. Confirm the correct viscosity grade for the ambient temperature range in which the equipment operates, and avoid mixing different oil types or using substitutes that could degrade film strength. During drain procedures, prepare a suitable collection container and thoroughly clean the drain plug area before reinstalling with a new washer if required. After an oil change, run the engine for a brief period to circulate the new oil, then recheck the level and top off as necessary. Proper oil management reduces friction in the crankcase, lowers operating temperatures, and helps prevent long-term engine damage.
The cooling system inspection should be performed with the engine off and cool, allowing the radiator and surrounding components to be accessible without the risk of burns. Check for unobstructed air flow to the cooling fins and ensure the fan operates freely without rubbing or unusual noise. Inspect hoses, clamps, and the radiator for signs of leaks, cracks, or soft spots, replacing any compromised components promptly. Clean any debris from the cooling fins and ensure the shroud is intact to maximize airflow. A functioning cooling system maintains engine performance, reduces thermal stress, and prevents overheating during demanding tasks.
Troubleshooting overheating conditions requires a structured approach to identify root causes without unnecessary disassembly. Start by verifying fuel delivery and ignition timing, as improper combustion can place additional load on the engine and raise temperatures. Monitor coolant level, cap integrity, and pressure if the system is sealed, since a loss of pressure can indicate a leak or gasket issue. Inspect the radiator and cooling fan for proper operation; a nonfunctioning fan or a blocked radiator dramatically increases heat buildup. If overheating persists after basic checks, examine for exhaust restrictions, contaminated oil, or a failed water pump, then pursue corrective action in a methodical sequence to restore safe operating temperatures.
Starting and electrical system
The starting and electrical system of the CRAFTSMAN M260 combines a robust battery setup with a reliable ignition and starter mechanism to ensure dependable cold starts and consistent performance. Begin by confirming that the battery matches the specified type and rating for the M260, typically a sealed lead-acid or equivalent rechargeable cell configuration suitable for outdoor power equipment. Ensure terminals are clean, tight, and free of corrosion, and verify that the charging system maintains proper voltage during operation. Regularly inspect the battery hold-down and case integrity to prevent movement that could lead to terminal stress or short circuits. A well-maintained electrical system reduces starting friction and improves overall reliability in varied weather and load conditions.
When performing battery charging procedures, use the charger and procedure approved by the manufacturer, monitoring voltage and current according to the service data. Avoid rapid charging that can reduce battery life, and disconnect the battery from loads during full-charge periods to prevent parasitic drains. After charging, check the electrolyte level if applicable and top up with distilled water only when the cells are exposed and per the manufacturer’s guidelines. Record charge cycles, terminal cleanliness, and any noticeable swelling or heat during charging, as recurring anomalies can indicate internal battery degradation or a failing cell that should be replaced to prevent starting failures.
The ignition system is designed to deliver a reliable spark at the right moment to ignite the air-fuel mixture. Inspect the ignition coil, spark plug, and related wiring for wear, cracks, carbon tracking, or loose connections. Replace worn or fouled spark plugs, maintain proper gap, and verify the ignition timing if service specifications indicate adjustments are required. Use manufacturer-approved replacement parts to preserve performance, and test the system using a spark tester to confirm a consistent, blue spark under load conditions. Regular inspection helps prevent misfires that can lead to hard starts or reduced engine efficiency.
In terms of electrical wiring harness inspection, follow a thorough visual and physical check for insulation wear, chafing, exposed conductors, and loose harness connections. Inspect all sensor and switch harnesses for secure mounting and proper routing away from hot surfaces or moving parts. Look for signs of moisture intrusion, corrosion at terminal connections, and ensure that relays are seating properly and making solid contact. Replace any damaged harness sections with OEM-approved loom and connectors to prevent intermittent faults that can affect starting behavior or engine performance.
Starter and recoil starter service covers the primary means by which the engine is cranked. For recoil starters, inspect the rope for fraying, replace if stretched or cracked, and confirm that the pulley spins freely without binding. If the starter handle is loose or the spring shows signs of wear, replace the assembly to maintain reliable engagement. For electric starters or backup starting devices, verify the motor brushes, solenoids, and power connections, ensuring that the starter engages smoothly without excessive current draw. Regular maintenance of the starter system reduces the likelihood of hard starts, reduces wear on the engine, and improves overall reliability during demanding yard tasks.
The air filter plays a crucial role in protecting the carburetor and combustion chamber from dust and debris. Begin by removing the air filter cover and carefully lifting out the element without tearing it. Inspect the filter for signs of oil saturation, tears, or excessive dirt buildup. If any of these conditions are present, replace the air filter with a new OEM part or a compatible equivalent. When reinstalling, ensure the filter sits flat and seals properly against the housing to prevent unfiltered air from entering the engine. Regular inspection and timely replacement help maintain optimal air flow and engine performance, reducing wear on the carburetor and extending the life of the engine’s intake system.
Carburetor cleaning is essential to remove varnish, gum, and fuel residues that can hinder fuel metering and air flow. Start by removing the carburetor from the engine following the manufacturer’s safe-disassembly procedures. Use a carburetor cleaner spray to dissolve buildup on the jets, emulsion tubes, and the throttle movement areas, taking care not to damage delicate parts. After cleaning, inspect gaskets, o-rings, and seals for cracks or deterioration and replace as necessary to prevent air leaks. Reassemble with clean, dry components and ensure all fasteners are tightened to the specified torque. A thorough cleaning restores proper fuel-air mixtures and smooth engine operation, especially after extended storage or poor fuel quality.
Idle speed and mixture adjustments ensure stable engine operation at low throttle and when idling. Begin with the idle speed screw set to the manufacturer’s recommended RPM for your model, using a tachometer if available. Next, adjust the idle mixture screw to achieve a steady idle with minimal exhaust smoke and stable ignition timing. If the engine surges or stalls at idle, recheck for air leaks, clogged passages, or insufficient fuel supply before making further adjustments. After setting idle, run the engine under varying loads to confirm that the mixture remains correct across typical operating conditions. Proper idle and mixture adjustments improve starting reliability, throttle response, and fuel efficiency.
The air intake duct inspection focuses on ensuring a clean, leak-free path for air to reach the carburetor. Inspect the entire duct for cracks, splits, or loose connections and replace damaged sections as needed. Pay particular attention to the duct clamps and fasteners to ensure a secure, vibration-free fit that won’t allow unfiltered air to bypass the filter. If you notice any loose fittings or degraded tubing, rectify them promptly to maintain consistent air flow and prevent lean or rich fuel mixtures. Regular inspection of the air intake path helps maintain engine efficiency, reduces the risk of foreign object ingestion, and supports reliable performance in varying operating conditions.
The drive belt is a critical component in the propulsion and performance of the chassis and drive system. Regular inspection should focus on belt wear, cracks, fraying, glazing, and proper tension. When inspecting, check for missing ribs, shredded edges, or any deviation from the manufacturer’s specified belt tension. Replacement should be performed using the exact OEM belt specified for the Craftsman M260 model to ensure optimal grip and power transfer. After installing a new belt, rotate the drive system by hand to confirm smooth operation without binding or excessive slack, and recheck tension according to the service data. In addition, inspect pulleys for grooves, wear, and alignment to prevent premature belt wear and potential slip conditions during operation. Always disconnect power sources and follow lockout/tagout procedures before performing belt work to maintain personal safety and system integrity.
The puley and shaft alignment section emphasizes maintaining precise alignment between pulleys and drive shafts. Misalignment can lead to accelerated wear, vibration, and reduced belt life. Begin by removing any covers that shield the drive area to gain clear access to the pulleys and shafts. Use a straightedge or laser alignment tool to verify that the pulleys run in parallel planes and remain true to each other. If misalignment is detected, adjust mounting points or shims as recommended by the manufacturer, and re-measure to confirm final alignment. When reassembling, ensure all fasteners are torqued to the specified values and that belts are seated in the pulleys evenly to prevent skew and uneven wear over time. Regular checks should be scheduled as part of routine maintenance to catch adjustments before problems escalate.
Brake system basics and inspection are essential for safe operation and reliable controlled stopping of the vehicle or equipment. Begin with a visual examination of all brake components for wear, fluid leaks, and signs of contamination. Check brake pads, shoes, and rotors or drums for thickness, glazing, and scoring. Inspect hydraulic lines and fittings for cracks, leaks, or abrasions, and verify that the brake fluid reservoir is at the proper level and contains the correct type of fluid. Performance testing should include a gentle, progressive brake application to confirm adequate bite and absence of pulling to one side. If any abnormal noise, vibration, or reduced braking efficiency is observed, diagnose the root cause promptly, inspecting calipers, linkage, and master cylinder for wear or air in the system, and bleed or replace components as necessary following the manufacturer’s procedures.
Wheel and transmission service focuses on ensuring smooth operation and long service life for moving components. Begin by inspecting wheel bearings for play, roughness, or uneven heat during rotation, and service or replace bearings as needed. Check wheel hubs for wear, corrosion, and secure mounting hardware, and ensure correct torque on lug nuts or fasteners per the service manual. Transmission service includes verifying gear engagement, shifting smoothness, and lubrication health. Replace lubricant according to the recommended intervals and specifications, and inspect seals and gaskets for leaks. When disassembling any part of the wheel or transmission, document the orientation of components to guarantee proper reassembly, and perform a functional test after maintenance to confirm that the drive operates without abnormal noise or resistance.
Maintenance schedules and records
Routine maintenance intervals for outdoor power equipment such as the CRAFTSMAN M260 are designed to maximize reliability and longevity. Establish a baseline schedule based on typical usage patterns, environmental conditions, and the operator’s manual recommendations. For regular users, anticipate more frequent checks on fuel systems, air filters, and lubrication, especially in dusty or high-usage scenarios. Establishing a documented routine helps ensure that essential tasks are not overlooked during busy seasons and provides a clear history for future diagnostics. Consistency in performing these tasks is more impactful than the exact interval on a calendar, as it maintains optimal engine performance and reduces unexpected downtime.
In general, routine inspections should align with engine hours and usage milestones rather than calendar dates alone. For example, check the air filter, spark plug, and fuel system every 25 hours of operation or monthly, whichever comes first. Change the oil and replace the oil filter at intervals specified by the manufacturer or every 50 hours of use in typical conditions. For equipment operated in fine dust or heavy debris, shorten these intervals to reflect the harsher operating environment. Keeping a log of hours, tasks performed, parts replaced, and observed abnormalities creates a valuable record that aids troubleshooting and resale value. This proactive approach helps prevent minor issues from expanding into major repairs.
Record keeping best practices emphasize thorough, legible, and durable documentation. Use a dedicated maintenance logbook or a digital spreadsheet with standardized fields: date, hours on the engine, task performed, parts used, part numbers, and any notes on performance or anomalies. Photograph critical components before and after service to provide visual references for future maintenance cycles. Attach receipts or warranty information for replaced parts to the record for traceability. Regular reviews of the maintenance history can reveal trends, such as recurring weak spots or parts that consistently require replacement, which informs supplier choices and maintenance budgeting. A well-maintained record system also supports safer operation by ensuring that important checks are never missed and that everything is within specification during inspections.
When to replace major components is determined by a combination of service life, symptom indicators, and manufacturer guidance. Common major components to monitor include the battery or electrical system, the carburetor or fuel injectors, the air filter housing, and critical mechanical linkages. Replace batteries before they show signs of failure, particularly in cold weather, to avoid abrupt downtime. Carburetor and fuel system components should be inspected for signs of varnish, leaks, or improper idle performance; replace or service as recommended by the manufacturer. The air filter and housing should be replaced when the filter media shows heavy clogging or damage that cannot be addressed by cleaning. Additionally, pedal, blade, or drive components should be inspected for wear and replaced when measurements exceed manufacturer tolerances. Scheduling proactive replacements based on hours or condition ensures consistent performance and reduces the risk of sudden, costly outages on the job site.
The CRAFTSMAN M260 lawn mower and similar outdoor power equipment can present a range of common symptoms that indicate specific failure modes. In many cases, symptoms such as hard starting, poor acceleration, rough running, or loss of power point to fuel delivery, ignition, or air intake issues. A systematic approach is essential to avoid guesswork and to prevent unnecessary part replacements. Start with a careful visual inspection for obvious problems like loose cables, damaged hoses, or signs of oil contamination. Documenting symptoms with date and operating conditions helps track recurring patterns that may reveal intermittent faults that are not evident during a single diagnostic pass.
Fuel-related symptoms are among the most frequent causes of performance issues. If the engine runs inconsistently or stalls, verify fuel freshness, correct octane rating, and absence of water or dirt in the tank. Check the fuel cap vent to ensure it is not clogged, as a blocked vent can create a vacuum that impedes fuel flow. Inspect the carburetor for varnish buildup and ensure the fuel filter and lines are clear. In cold-weather conditions, ensure the choke and primer procedures are functioning correctly, as improper operation can lead to extended cranking and difficult starting. A clean air filter is critical; a restricted filter reduces airflow and can cause rich running or stalling, especially under load.
Electrical and ignition symptoms require careful testing of the ignition system and safety interlocks. If there is no spark or weak spark, inspect the ignition coil, grounding points, and spark plug condition. Verify that the kill switch and safety interlock system are wired correctly and functioning—faulty interlocks can cause no-start conditions or sudden shutdowns. When starting is difficult but the engine cranks, check for battery health in electric-start models and ensure the charging system maintains proper voltage. Corroded connectors or damaged wires are common culprits; clean or replace as needed and recheck continuity with a multimeter. Finally, ensure the correct gap on the spark plug and observe proper torque when fitting new plugs to avoid misfires or overheating.
Air and exhaust-related symptoms often relate to airflow restrictions or exhaust restrictions. A clogged air intake or dirty air filter reduces engine performance, while a restricted exhaust or muffler can cause backpressure issues and overheating. Inspect the carburetor intake boots for cracks and ensure there are no missing or loose intake gaskets. If the engine experiences power loss under load, test for air leaks around the carburetor and intake manifold seals. Clean the carburetor jets if fuel delivery appears improper, and verify that the idle and high-speed adjustments are set according to the manufacturer's specifications. Ensure the cooling fins and cooling system are free of debris to prevent overheating and potential performance degradation.
Step by step diagnostic flow
Begin with a safe, thorough assessment by ensuring the machine is on a stable surface and the ignition is disabled during inspection. Start with symptom verification: reproduce the condition if possible and note runtime, load, and environmental conditions. Next, perform a fuel system check by testing fuel quality, line integrity, filters, and carburetor cleanliness. If fuel systems pass the inspection, shift to the ignition and electrical circuits, testing for spark, coil integrity, wire continuity, and safety interlocks. When ignition and fuel are confirmed, evaluate the air intake and exhaust pathways for restrictions, inspecting filters, gaskets, and mufflers. Finally, consolidate findings, compare against service manual specifications, and determine whether adjustments, cleaning, or part replacement is warranted. Maintain a log of measurements and outcomes to guide future maintenance decisions.
Parts replacement guidelines
Only replace parts that show measurable wear or failed function according to the manufacturer’s specifications. For fuel system components, replace the fuel filter and lines if there is evidence of cracking, swelling, or contamination, and consider carburetor rebuild kits if varnish buildup is extensive. In the ignition system, replace worn spark plugs, inspect ignition coils for proper resistance readings, and replace any damaged wiring harnesses or connectors to restore reliable spark and kill-switch operation. For air intake, replace severely clogged air filters and damaged intake boots, ensuring gaskets are sealed to prevent air leaks. Exhaust and cooling components should be replaced when there is excessive corrosion, holes, or restricted flow that cannot be remedied through cleaning. When reassembling after part replacement, use the correct torque values for fasteners and verify that safety interlocks and guards operate correctly before returning the machine to service.