CRAFTSMAN 247.374300 Service Manual

Overview and system overview

The CRAFTSMAN 247.374300 is a compact outdoor power equipment unit designed for reliable performance in a variety of yard tasks. This section provides a comprehensive understanding of the machine’s core systems, their interrelations, and the essential safety practices required during operation and maintenance. A solid grasp of the overall architecture helps technicians diagnose issues efficiently and perform repairs with confidence, minimizing downtime and ensuring user safety. The service manual emphasizes a methodical approach to inspection, disassembly, reassembly, and benchmarking against manufacturer specifications to preserve performance and longevity. By detailing safety procedures, tooling, parts identification, and troubleshooting fundamentals, technicians can establish a structured workflow for routine maintenance and problem resolution.

Safety procedures and proper use are foundational to any service activity involving outdoor power equipment. Always begin with a thorough safety assessment, including disconnecting power sources and draining fluids when required, to prevent accidental starts or exposures. Personal protective equipment (PPE) should be selected based on observed risks, such as eye protection for debris, gloves for sharp edges, and hearing protection when operating noisy components. Understand and follow the manufacturer’s warning labels and the machine’s user manual to avoid common hazards like kickback, hot surfaces, and stored energy. Establish a clean, well-lit workspace with proper ventilation if fuel systems are involved, and keep fire suppression equipment nearby when dealing with flammable fuels. Documentation of safety checks before, during, and after service helps ensure adherence to best practices and provides a record for warranty and liability considerations.

Tooling and parts identification is critical to accurate maintenance and prompt repairs. Create a verified list of required tools, including standard and metric wrenches, pliers, screwdrivers, torque wrenches, and specialty gauges as specified in the manual. Always confirm part numbers against schematics and exploded views to avoid introducing incompatible components. Keep a clearly labeled inventory of consumables such as lubricants, seals, and gaskets, and ensure replacements meet OEM specifications for material compatibility and performance. When removing fasteners, note their length, thread type, and position to prevent misassembly. Proper identification also extends to electrical connectors, hoses, and fuel lines, where color codes and labeling aid in restoring correct routing and connections.
A systematic approach to tooling and parts reduces downtime and enhances repair accuracy, helping technicians restore original performance levels more reliably.

Troubleshooting fundamentals form the backbone of efficient diagnosis. Begin with a staged approach: confirm basic functionality, verify fuel and ignition conditions, and then assess mechanical integrity. Use diagnostic routines to isolate subsystems, such as ignition, fuel delivery, air intake, and power transmission, before diving into complex component tests. Document observed symptoms with time stamps, operating conditions, and environmental factors to identify patterns that point to root causes. When measurements deviate from factory specifications, use calibrated test equipment and refer to tolerance charts to determine acceptable variance. Safety interlocks and switch circuits should be tested to ensure they function correctly, as many issues originate from signaling faults rather than mechanical failure. Finally, create a concise service plan that prioritizes corrective actions, part availability, and potential downtime, enabling a predictable turnaround for customers.

CERTIFIED OUTDOOR POWER EQUIPMENT MAINTENANCE AND REPAIR

The following technical manual section provides detailed assembly and disassembly procedures for the CRAFTSMAN 247.374300. It is written to support a professional technician in the field with clear step-by-step guidance, safety considerations, and practical tips to ensure correct reassembly and reliable operation. Adhere to standard safety practices, including disconnecting power sources, wearing appropriate PPE, and following manufacturer torque specifications when reassembling components. The procedures herein emphasize proper handling of fasteners, alignment checks, and inspection of mating surfaces to prevent damage during service. Begin by organizing a clean, well-lit work area with labeled containers for hardware and replacement parts to maintain accuracy during reassembly.

Removing external components

External components should be removed in a logical sequence to prevent accidental damage and to preserve the integrity of attach points. Start by disconnecting the power source and removing any protective shrouds or guards using the appropriate hand tools. Carefully detach control cables, linkages, and electrical connectors, noting their routing and fastening points for correct reinstall. When removing exterior panels or housings, support larger pieces to avoid bending or cracking and retain fasteners in their original positions to prevent misplacement. After each component is removed, inspect fastener holes for debris and clean as necessary to ensure proper thread engagement during reassembly. Keep a detailed record or photograph of the disassembly to aid reference during reassembly and troubleshooting later in the process.

Accessing engine and drive system

Access the engine and drive system by removing the remaining covers and shielding that protect these assemblies, ensuring you maintain an orientation reference for reassembly. Follow the service manual’s sequence to detach the drive belt or chain, tensioning devices, and pulleys while taking care to relieve any stored energy in tensioned components. When separating the engine from the frame, support the weight with stands or a helper to avoid dropping the unit and causing damage to mounting points or the crankcase. Inspect all mounting bosses, fasteners, and isolation mounts for wear or deformation and replace any compromised parts before proceeding. As you gain access to the internal components, log the condition of gaskets, seals, and lubrication ports, replacing where indicated by wear or leakage, and prepare replacement parts in the same orientation to simplify reassembly.

Replacing wear parts and consumables

With access gained, identify all wear parts and consumables that require replacement according to the service intervals and current condition. Replace air filters, fuel filters, spark plugs, lubricants, and any worn belts or drive components using manufacturer-specified torque values and alignment procedures. Inspect cooling passages, fins, and the muffler area for buildup and signs of overheating, cleaning or replacing parts as needed while preserving proper clearance and airflow. When reassembling wear parts, ensure seals and gaskets are installed correctly to prevent leaks, and apply a light film of lubricant to moving interfaces if specified by the manufacturer. After installation, perform a functional test of the engine and drive system, checking for smooth operation, proper belt tension, and absence of abnormal noises or vibrations. Finally, recheck all fasteners to their specified torque values and restore external components, grommets, and protective shields in their original positions for safe, reliable operation.

Fuel system inspection is a critical starting point for reliable engine performance. Begin by visually inspecting all fuel lines and hoses for signs of cracking, hardening, or leakage, and replace any components that show wear. Check the fuel tank and cap for proper sealing and any signs of rust or contamination that could restrict flow. Use a clean receptacle to drain fuel from the sediment bowl and fuel line to inspect for water, debris, or varnish buildup. Inspect the fuel filter or screen if equipped, removing and cleaning or replacing it as needed to ensure an unobstructed fuel path to the carburetor. Finally, verify that the fuel pump (if present) operates smoothly and delivers consistent pressure, listening for humming sounds that indicate normal function or signs of failure.

Carburetor troubleshooting and adjustment requires a methodical approach to restore correct air-fuel mixture. Start by removing the air filter and inspecting the carburetor body for signs of varnish or gum deposits, which can impede performance. Clean the carburetor using manufacturer-approved solvents, taking care not to damage jets, needles, or slide mechanisms. Check the idle speed and mixture screws, turning them gradually to achieve a stable idle without stalling or rough running. If the engine exhibits hard starting, flooding, or rich running, inspect the choke mechanism for sticking or improper operation and verify that the primer bulb (if equipped) functions correctly. Reassemble the components carefully and perform a diagnostic run to confirm improvements across idle, acceleration, and full-throttle operation.

Ignition system service is essential for reliable starting and consistent power output. Begin by inspecting the spark plug for proper gap, fouling, or unusual deposits, and replace the plug if its condition indicates wear or contamination. Check the ignition coil, kill switch, and wiring for continuity and secure connections, repairing any damaged insulation or loose terminals. If the engine experiences misfiring or lack of spark, test the ignition module (if present) and confirm that the flywheel magnet passes the pickup coil without excessive play. Ensure the ignition timing is correct according to the service specifications and adjust only when required using the appropriate tools and procedures. After servicing, perform a cold and warm start test to ensure reliable ignition across operating temperatures and load conditions.

The electrical system of the CRAFTSMAN 247.374300 features a consolidated set of components designed to manage power delivery, safety interlocks, and operator controls. Understanding the layout and function of each element is essential for accurate diagnostics and reliable repair. This section provides a comprehensive overview of wiring diagrams, charging and battery maintenance, and safety interlock and switch checks, with practical steps for verification and testing. Begin by confirming battery type and system voltage, then proceed to tracing circuits according to the wiring diagram to isolate faults without introducing damage to sensitive components. Approaches described here emphasize safe handling practices and methodical troubleshooting to minimize downtime and ensure operator safety.

Wiring diagrams overview involves interpreting the schematic layout used for the 247.374300. The diagrams illustrate power paths from the charging system through the battery, through ignition or operator controls, and to essential loads such as safety switches and the engine or motor control circuits. When examining these diagrams, verify color codes, connector orientations, and harness routing to detect pinched or corroded connections. It is important to document any deviations from the factory diagram, including aftermarket modifications, to avoid misinterpretation during repairs. A systematic approach includes verifying continuity, resistance, and insulation resistance across circuits while cross-referencing with the physical harnesses and component locations. Always ensure the battery is disconnected before performing resistance checks on high-current paths to prevent accidental arcing or component damage.

Charging and battery maintenance covers the proper care and inspection of the battery, charging system, and related safety devices. Regular inspection should include checking battery terminals for corrosion, ensuring snug and clean connections, and confirming that the charging system maintains proper voltage without excessive ripple or voltage drop under load. For lead-acid batteries, monitor electrolyte levels if applicable and top up with the recommended solution. When testing the alternator or charger, use a multimeter to measure charging voltage at the battery terminals under idle and no-load conditions, and compare results to the manufacturer’s specifications. If charging performance is inconsistent, inspect the wiring harness for damaged insulation, loose grounds, or failed fuses, and test the state of charge using a reliable hydrometer or a digital battery tester. Replace worn or damaged cables and ensure that the battery hold-downs are secure to prevent movement that could degrade terminal connections during operation.

Safety interlock and switch checks focus on ensuring that operational safety devices function correctly to prevent machine operation under unsafe conditions. Begin by verifying that interlock switches engage properly when protective guards or covers are closed, and that they immediately disable power when opened. Use the recommended test procedure to simulate guard openings and confirm that the control circuit responds with an immediate shutdown signal. Inspect all switch actuators for smooth operation, free from binding or misalignment, and ensure that any mechanical linkage is correctly adjusted to produce a clear and positive electrical state change. Electrical checks should include verifying continuity when the interlock is engaged and confirming open circuits when disengaged, using a calibrated multimeter. Document any anomalies, such as delayed shutdowns or intermittent switch behavior, and trace the fault to wiring, connectors, or the switch itself with careful inspection and systematic testing to prevent safety compromises during subsequent use.

Lubricant specifications and intervals: For optimal performance and longevity of the Craftman 247.374300, adhere to the manufacturer’s recommended lubricant types and service intervals. Use high-quality, viscosity-appropriate engine oil and gear lubricant as specified in the engine and transmission manuals, ensuring they meet or exceed the OEM standards. Check the oil level and condition at regular operation intervals, and replace or top off according to usage hours and operating environment. When changing lubricants, follow a clean process to prevent contamination, using clean funnels and containers, and disposing of used oil in accordance with local environmental regulations. Maintain a record of all lubricant changes, noting the date, hour meter reading, and any observations about oil color or consistency, which can indicate internal wear or contamination. Use proper seals and gaskets during oil fill to prevent leaks, and ensure the breather system remains unblocked to avoid pressure buildup that could force oil past seals.

Cooling system inspection and maintenance: The cooling system is critical to preventing overheating during extended operation. Regularly inspect hoses, clamps, radiators, and the coolant reservoir for signs of wear, cracks, or leaks. Verify that the coolant mixture ratio matches the manufacturer’s specification, typically a precise blend of water and approved antifreeze, and replace coolant at intervals recommended by the manual to prevent corrosion and scaling. Clean the cooling fins and air passages to maximize airflow, removing debris, leaves, and grass clippings that can impede heat transfer. Check the thermostat and water pump for proper operation, replacing any faulty components promptly to maintain consistent engine temperatures. Ensure the radiator cap maintains proper pressure, and inspect the overflow system for blockages or leaks that could compromise cooling efficiency.

Troubleshooting leaks and overheating: Leaks can originate from seals, gaskets, or wear points in the lubrication and cooling circuits. When a leak is detected, perform a thorough inspection to trace the source, cleaning the area to identify fresh fluid and using UV dyes if necessary for precise localization. Address minor leaks with appropriate sealants or replacement gaskets, but do not overlook root causes such as overfilling, excessive pressure, or degraded hoses. Overheating symptoms, such as rising coolant temperature, high exhaust temperatures, or warning indicators, require immediate action to prevent engine damage. Check coolant level, verify proper fan operation, and inspect for airflow obstructions before continuing operation. If overheating persists after basic checks, perform a controlled shutdown, allow the system to cool, and evaluate the cooling components for wear or failure, scheduling professional service if necessary to avoid long-term harm.

The belt drive and cutting systems in the CRAFTSMAN 247.374300 mower rely on precise tension, alignment, and clean, sharp components to deliver reliable cutting performance. Start with a systematic approach to inspection, ensuring that all belt surfaces are free of oil, dirt, and signs of glazing or cracking. When you detect any irregular wear, replace belts using the manufacturer's recommended part numbers and torques, and recheck belt tracking after installation. Proper tension is critical; under-tensioned belts slip and under-perform, while over-tensioned belts put excessive load on pulleys and bearings, shortening component life. Before running the engine, manually rotate the blade assembly to ensure smooth operation and absence of unusual noises or binding. A regular preventive routine will extend the life of the belt drive and improve cutting consistency across the full width of the deck.

Tensioning and alignment procedures begin with removing blades and guarding to access the belt path without obstructions. When tensioning, use the specified tension values from the service manual and apply them evenly across both belts to prevent asymmetrical wear. Align the pulleys so that the belt runs true in the center groove and does not wander toward the edge of the pulley. A misaligned belt can wear sidewalls quickly, reduce efficiency, and create dangerous heat build-up. After setting tension and alignment, rotate the drive by hand to confirm there is no rubbing or flutter in the belt, and then perform a cautious engine-start test to verify stable operation before returning the mower to service. Keep a log of tension readings and alignment checks to monitor changes over time and schedule preventive maintenance accordingly.

Blade and spindle service requires careful inspection of blade balance, edge condition, and mounting integrity. Dull, nicked, or unbalanced blades create vibration, degrade cut quality, and accelerate spindle bearing wear. Remove all blades using proper tools and securely reinstall with the correct blade orientation and locking hardware. Check spindle bearings for smooth rotation with no side-to-side play or audible roughness; replace bearings if any play or noise is detected. Inspect the blade adapters and mandrels for cracks or wear, and ensure all fasteners are torqued to the recommended values. When reassembling, recheck belt tension and deck alignment to confirm that the cutting action remains precise and the deck sits level relative to the ground surface. Performing thorough blade and spindle service enhances cut quality, reduces wear on the belt drive, and promotes safer operation overall.

Safety shield and guard inspection is essential to protect users from moving parts and to maintain compliant operating conditions. Visually inspect all shielding for cracks, deformation, or missing fasteners and replace any damaged components promptly. Ensure all guards clear the blade tips with adequate clearance and do not contact the belt or pulleys during full travel through the cutting cycle. Verify that the safety interlocks and brake mechanisms engage properly and that any shield springs retain adequate tension for reliable operation. Clean shields and guards to remove grass build-up, which can obscure fasteners or misalign shields, and reassemble with correct spacing and alignment. Regular guard inspection reduces the risk of injury and contributes to consistent deck performance, making maintenance practical and safer for future use.

Diagnostics and troubleshooting guide

Symptom based fault identification begins with a systematic approach to observe, measure, and correlate operating conditions with observable symptoms. Start by noting the exact mower or equipment behavior, such as failure to start, unusual noises, loss of power, or intermittent operation. Gather baseline information including model, serial number, reported maintenance history, and recent usage patterns. Use a process of elimination by checking simple, non-invasive factors first, such as fuel quality, battery condition, safety switch alignment, and obvious obstructions in air filters or cooling fins. Document each symptom with as much detail as possible, including when it occurs (starting, running, under load), environmental conditions, and any recent maintenance performed. This careful documentation helps pinpoint likely fault domains and reduces time spent on broader, less probable causes.

Common failure points and fixes cover the most frequently encountered issues in this specific service manual context. Electric and starting components often present as dead circuits, so verify battery voltage, fuses, and wiring continuity before replacing parts. Carburetion and fuel delivery problems typically manifest as hard starting, rough idle, or stalling; inspect fuel lines for leaks, check the carburetor for varnish deposits, and ensure the fuel pump and filters are functioning properly. The cutting system frequently presents as reduced performance or unusual noise; inspect blade condition, spindle bearings, and belt tension, replacing worn components as needed and ensuring proper alignment. Electrical systems can show symptoms like inconsistent RPMs or erratic sensor readings, so scan for loose grounds, corrosion at connector pins, and degraded insulation. Finally, safety interlocks must be verified to ensure the unit can operate only under safe conditions; test each interlock circuit with the appropriate troubleshooting steps and confirm correct switch actuation. Each fix should be followed by a functional test to confirm the symptom is resolved before moving to the next suspected fault.

Preventive maintenance checklist emphasizes proactive care to minimize unexpected failures and extend service life. Establish a routine inspection interval that includes checking air filters, fuel quality, oil levels, and cooling fins, cleaning components as needed to prevent dirt ingress. Regularly inspect and replace worn belts, blades, and bearings to maintain safe and efficient operation; maintain proper tension and balance to reduce vibration and noise. Implement a fuel and lubrication schedule aligned with usage hours, ensuring fresh fuel and appropriate oil grade, and perform an overall system cleanliness sweep to remove dirt and debris that could compromise performance. Document maintenance actions with dates, parts changed, and observed conditions, enabling trend analysis over time to catch creeping issues before they become major faults. Train operators to recognize early signs of trouble and to report changes promptly, creating a feedback loop that supports consistent reliability and safer operation of the equipment.

In-depth diagnostic scenarios in this guide reflect practical field realities and emphasize reproducible testing. When a symptom is reported, reproduce it under controlled conditions to observe exact behavior and verify suspect components. Use diagnostic tools recommended by the manufacturer, such as a multimeter for electrical checks or a carburetor cleaning kit for fuel system work, ensuring all safety procedures are followed. If a fault is not readily identifiable, proceed with a structured approach: isolate power sources, test subsystems independently, and replace only components with confirmed failure indicators. After repairs, perform a comprehensive test run under typical operating loads to confirm normal performance and to prevent recurrence of the original symptom. Maintain thorough records of diagnostic steps, test results, and final resolutions to support future maintenance and warranty considerations.

The Craftsmanship and reliability of the 247.374300 are enhanced when storage and long term care are performed correctly. Begin by inspecting the unit for any signs of wear or damage before placing it into long-term storage. Clean all exterior surfaces to remove dirt, dust, and corrosive residues, ensuring air vents and cooling openings remain unobstructed. Remove any fuel from the engine if recommended by the manufacturer, and follow precise guidelines for fuel stabilization to prevent varnish buildup. Store the machine in a clean, dry area with stable ambient temperatures to minimize condensation and corrosion risks. Keeping a designated, well-ventilated space away from direct sunlight protects plastics and rubber components from degradation over time. Regularly verify that moving parts are properly lubricated as described in the maintenance schedule, even when the unit is not in active use, to prevent seizing during the next startup.

Seasonal storage guidelines are designed to fit within the typical usage cycle and help maintain performance when work resumes. Before storing, complete any due maintenance tasks, including air filter inspection or replacement, spark plug care, and fuel system checks as prescribed in the service manual. Drain or stabilize fuel per the guidelines to avoid gum formation that can hinder starting and idle quality. Disconnect the battery if the unit will be idle for an extended period, following the safe procedures to prevent discharge and maintain battery health. Protect the fuel lines and fittings from temperature extremes by ensuring adequate insulation or enclosure within the storage area. When possible, elevate the unit slightly to promote air circulation under the chassis and reduce moisture contact with the underside. Document the date of storage and any observed conditions to assist with future service planning and warranty compliance.

Battery preservation during idle periods focuses on maintaining charge and preventing sulfation or chemical degradation. If the battery is removable, disconnect the terminals and store in a cool, dry place away from metal objects that could cause short circuits. Use a compatible battery maintainer or charger that adheres to the manufacturer’s voltage and amperage specifications, and monitor the charging process to avoid overcharging. Periodic rechecking of the battery’s state of charge, at intervals recommended in the manual, helps prolong life and readiness. Clean terminals and connectors prior to reinstallation to ensure a solid, low-resistance connection. Inspect the battery case for any signs of swelling or leakage, and replace compromised units promptly to avoid damage to electrical components. Keep the battery away from freezing temperatures, which can reduce capacity and accelerate degradation.

Sanitation and corrosion prevention emphasize reducing moisture, corrosive residues, and biological growth on metal surfaces. Wipe down all metal components with an appropriate rust-inhibiting solvent or coating that is compatible with the metal type and finish. Apply a light, protective film to exposed metal surfaces to deter galvanic reaction when exposed to humidity or salt air. Use approved cleaners for aluminum or steel parts, avoiding abrasive materials that could scratch protective coatings. Ensure all fasteners, clamps, and connectors are clean and lightly lubricated to prevent rust and seize during later removal. Store the unit with sufficient airflow to minimize humidity buildup inside enclosures and behind panels. Finally, perform a quick post-storage check upon return to service, verifying that hoses, cables, and safety switches are in proper condition and that no corrosion has developed on critical fasteners or contact surfaces.