CRAFTSMAN 917.387440 Service Manual

Overview and safety information

The Craftsman 917.387440 service manual provides structured guidance for diagnosing, repairing, and maintaining this outdoor power equipment model. It outlines standard procedures, recommended torque values, wiring diagrams, and generic troubleshooting steps designed to restore performance while preserving safety and reliability. This document serves technicians who expect clear, repeatable instructions and precise specifications to ensure proper operation after maintenance or repair. While the manual is comprehensive, it emphasizes verifying safety interlocks, verifying fuel and lubrication conditions, and confirming correct assembly before returning the equipment to service. Understanding the model’s baseline specifications and common failure modes helps technicians determine whether a repair is within scope or requires specialized service support.

Manufacturers emphasize consistent safety practices due to the combination of rotating blades, hot surfaces, and fuel exposure present in lawn and garden equipment. The manual highlights the necessity of removing power sources before disassembly, relieving stored energy in springs or tension devices, and ensuring that blades are secure after reassembly. It also covers the importance of performing work in a well-ventilated area away from sparks or ignition sources when handling fuel systems. Following these precautions reduces the risk of injury, fire hazards, and environmental contamination. Documented safety checks, such as inspecting guards, shields, and safety switches, are essential to maintaining a compliant and reliable repair process.

Tools and parts notation used in the manual are standardized to facilitate clear communication between technicians and service centers. The manual assigns specific abbreviations to common components, such as belts, pulleys, carburetors, and electrical harnesses, enabling quick reference without ambiguity. It also explains the color-coding and labeling conventions for wiring diagrams, as well as the sequence for disassembly and reassembly to preserve the integrity of fasteners and components. The notation extends to torque specifications, lubrication points, and part replacement guidelines, ensuring that technicians can reproduce repairs with consistent quality. Proper interpretation of these notations is critical to achieving reliable performance and prolonging the service life of the equipment.

The overview section also stresses the importance of keeping accurate service records, including part numbers, applied service procedures, and test results after repair. Detailed documentation supports warranty compliance and future troubleshooting by providing a historical context for the machine’s maintenance history. The manual encourages technicians to perform functional tests after reassembly, such as verifying blade stop positions, checking belt tension, and confirming safe operation of the engine and electrical systems. By adhering to these practices, technicians can deliver a safe, efficient, and durable repair that stands up to real-world use in demanding outdoor environments.

In summary, the overview and safety information establish the framework for professional servicing of the Craftsman 917.387440. It combines practical repair guidance with rigorous safety standards and clear part notation to help technicians execute accurate repairs while maintaining the highest level of operator safety. The section aims to equip you with a holistic understanding of the manual’s structure, ensuring you can navigate diagnostic steps and corrective actions with confidence. This foundation is essential for achieving dependable performance and extending the equipment’s service life through meticulous maintenance and repair.

The CRAFTSMAN 917.387440 represents a compact, mid-range outdoor power equipment unit designed for residential lawn care tasks. This model typically integrates a gasoline-powered engine with a mechanical drive system and a range of cutting or mulching attachments depending on the configured deck size and accessory package. The overall construction emphasizes durability with a steel deck, rugged fasteners, and a protective shroud to minimize exposure to moving parts. Access to internal components is facilitated by serviceable panels and a straightforward layout that supports field maintenance without specialized tools. Proper identification of model and serial numbers is essential before service to ensure correct parts compatibility and safety compliance.

Specifications for the craftsman model encompass engine displacement, horsepower or kilowatt rating, and performance metrics such as blade speed, cutting width, and recommended operating conditions. The drive system typically employs a belt-driven or hydrostatic or mechanical transmission, which translates engine power to wheel or ground-drive movement. Fuel capacity, oil type, and recommended maintenance intervals are included to guide routine servicing and prevent premature wear. The deck design, including cutting height ranges and adjustment mechanisms, is specified to help operators tailor performance to grass height and terrain. Electrical components, safety interlocks, and starting procedures are also defined to promote safe and reliable operation.

Key components and system layout focus on how major subsystems interact within the 917.387440. The engine sits at the core, driving a belt or shaft arrangement that powers the traction system and any auxiliary drives for attachments. A blade assembly or cutting mechanism is mounted under the deck, with a spindle shaft and bearings that require periodic lubrication and inspection for play or wear. The cooling system is typically air-cooled, with flywheel cooling fins and clean airflow paths that must be kept unobstructed. A handlebar or controls cluster includes throttle, choke, and engagement levers, all of which are integrated with safety switches to shut off power under certain conditions. The electrical harness links the ignition system, safety interlocks, and charging system to monitor battery voltage or alternator output where applicable. Accessory attachments, such as baggers or mulching kits, attach to dedicated mounting points and are routed through brackets that minimize vibration and noise.

Electrical and fuel system details describe how power is supplied and controlled. The engine uses a two- or four-stroke design depending on the specific variant, with a fuel delivery system comprising a carburetor, fuel lines, and a tank that requires proper venting and periodic inspection for leaks. Spark plug current, ignition timing, and priming procedures are outlined to assist with reliable starting in different ambient temperatures. The fuel system requires attention to ethanol content and storage practices to prevent phase separation or varnish buildup. Electrical components include a spark arrestor (where required), safety interlocks, and a consolidated control module that coordinates starting, blade engagement, and blade brake functions. When servicing the electrical system, disconnecting the spark plug wire before handling components is a standard precaution to prevent accidental starts. Regular inspection of the wiring harness, connectors, and protective shielding helps prevent shorts and electrical fires. Maintenance procedures for the fuel system, such as carburetor cleaning or diaphragm replacement, should follow manufacturer-recommended intervals and use compatible parts to preserve performance and emissions compliance.

Diagnostics and common issues

Symptom based troubleshooting begins with clear observation of any abnormal performance. Start by noting when the issue occurs, such as during startup, under load, or after a period of inactivity. Verify basic operating conditions first: fuel quality, air filter condition, and proper lubrication levels. Inspect for obvious signs of wear or damage, including loose fasteners, damaged belts, or excessive vibration. When a symptom is observed, document ambient conditions, engine temperature, and any unusual noises to guide the diagnostic process. A methodical approach helps isolate whether the problem is electrical, fuel, ignition, or mechanical in nature, reducing unnecessary part replacements and downtime.

Error codes and diagnostic procedures require access to any indicator lights, fault codes, or abnormal sensor readings. If the operator interface displays codes, cross-reference them with the manufacturer’s error code guide to determine probable subsystems involved. Use a calibrated multimeter to verify continuity and voltage levels at ignition coils, sensors, and control modules, ensuring readings are within specifications specified for the model. When codes indicate a misfire or sensor fault, perform targeted checks such as spark plug integrity, coil resistance, or throttle position sensor alignment. Document all measurements, note any code history, and perform a controlled test run after each corrective action to confirm resolution and prevent false positives. Adhere to safety procedures during electrical testing to prevent shock or short circuits and to avoid damage to sensitive control circuitry.

Common failure modes and preventative checks focus on predictable wear points and routine maintenance items. Fuel system issues often arise from stale gasoline or clogged injectors; perform a thorough fuel system inspection, including line pressures if accessible, injector spray pattern, and fuel filter condition. Air intake restrictions, dirty filters, and compromised carburetion can yield power loss and abnormal idling; replace filters or clean the carburetor as indicated by service literature and wear patterns. Wear in drive belts, pulleys, and anti-vibration mounts can manifest as belt slip, noise, or reduced performance; inspect for correct tension, alignment, and signs of glazing or cracking. Electrical connectors should be checked for corrosion, looseness, or heat damage; reseat, clean, and apply dielectric compound where recommended by service data. Implementing a preventative checklist that includes fuel, air, ignition, and exhaust system evaluations at defined service intervals helps maintain reliability and reduce the likelihood of recurring failures.

Removal and installation procedures

The following procedures provide a thorough, step-by-step approach to removing and reinstalling major assemblies on the CRAFTSMAN 917.387440. Begin with a clear workspace, disconnect the battery or power source as applicable, and ensure the engine is cool before handling any components. Use proper lifting techniques and secure the mower on a stable surface to prevent movement during removal. Keep all fasteners organized and labeled to match their original locations during reassembly. Document any unusual wear or damage observed during disassembly to assist with future maintenance planning or part replacement.

Engine removal and installation requires careful access to mounting points, fuel lines, and electrical connections. Start by relieving fuel pressure and disconnecting the fuel line from the carburetor, then cap the line to prevent spills. Remove the vacuum and breather hoses with attention to keeping them labeled for reuse. Unbolt the engine mount hardware in a systematic sequence, supporting the engine with a jacking tool or a transmission jack as you loosen the final fasteners. When lowering the engine, guide it away from the frame without striking surrounding components, then set it on a suitable stand or pallet for inspection. Reinstallation reverses these steps, ensuring all mounts are torqued to specification, fuel lines are properly routed, and electrical connections are reconnected with correct polarity and secure fasteners. Test the engine idle and check for leaks after installation, making any necessary throttle linkage adjustments to restore proper operation.

Mower deck and drive system disassembly involves disconnecting power transmission links, removing belt guards, and safely lowering the deck. Begin by releasing belt tension and removing the drive belt from pulleys, noting routing for correct reassembly. Detach the deck mounting bolts from the chassis, then carefully lift the deck away, supporting it to prevent bending the spindle shafts. If the mower features a mulch kit or discharge chute, remove these accessories separately and store them in a secure location. Inspect spindle bearings, blades, and the deck surface for wear or damage, replacing components as needed. When reinstalling, align the deck with mounting points, reattach the drive belt with proper tension, and reattach any guards or chutes. Ensure all electrical connections associated with the deck motor or sensors are secured and free of interference with the moving parts of the drive system. After reassembly, verify deck level and height settings, and perform a functional test to confirm smooth operation across all cutting heights and speeds.

Electrical harness and component replacement requires careful identification of harness routing, connector types, and ground points to maintain system integrity. Begin by labeling or photographing harness routes before disconnecting any connectors to ensure accurate restoration. Remove any protective covers or conduit sections that impede access to the malfunctioning component, then exchange the faulty part with an OEM replacement. When installing a new harness segment or component, verify compatibility with the model and confirm that all connectors mate only with their corresponding counterparts to avoid miswiring. Reinstall protective covers, ensure proper routing away from hot surfaces or moving parts, and secure all harness clamps to prevent chafing. After reconnection, perform a continuity check with a multimeter, inspect for loose grounds, and run a diagnostic procedure to confirm that all electrical subsystems communicate correctly and function as designed. Finally, confirm there are no warning lights or fault codes on the instrument cluster and verify overall engine performance and safety interlocks during a brief test run.

Maintenance and service intervals

Establishing a regular maintenance routine is essential to extend the life of your outdoor power equipment and to ensure safe, reliable performance. Begin by documenting the exact dates of each service action and the operating hours at the time of service. For most Craftsman units, a baseline maintenance interval is every 25 hours of use or every season, whichever comes first, with more frequent attention in dusty or extreme operating conditions. It is important to align the schedule with manufacturer recommendations, but practical usage patterns will often dictate minor adjustments. A well-kept maintenance log helps you track wear items, fluid levels, and blade or belt condition, allowing you to anticipate replacements before failures occur. When in doubt, err on the side of more frequent inspections rather than delaying critical checks until a breakdown occurs.

Routine maintenance should begin with a visual inspection for loose components, damaged cords or hoses, and obvious signs of wear. Check belts for cracks or fraying, inspect pulleys for wobble, and verify that guards and covers are secure. Cleaning the engine compartment and cooling fins helps prevent overheating and extends engine life. Replace or clean air and fuel filters as recommended by the manufacturer, and inspect fuel lines for cracking or hardening. Keep the machine free of debris such as grass, dirt, and leaves that can impede performance and cause overheating. A clean machine also makes it easier to spot potential problems during later inspections, reducing the chance of unexpected downtime.

Lubrication, filters, and fluid recommendations are critical to maintaining smooth operation and preventing premature wear. Follow the specified intervals for lubricating moving parts and applying the correct type of grease or oil to joints, bushings, and fittings. Check and replace engine oil according to the manufacturer's schedule, paying attention to correct oil grade and capacity. If the equipment uses hydrostatic or hydraulic systems, monitor fluid levels and top off with the recommended fluid while ensuring the system is cool and free of contamination. Filter maintenance should follow the recommended replacement intervals, and any signs of clogging or reduced flow should prompt earlier service. Always use fresh, correctly rated fluids and avoid mixing different oils unless explicitly approved by the manufacturer to prevent varnish buildup and reduced performance.

Tightening torques and fastener specifications are essential to maintain structural integrity and safe operation. Use a calibrated torque wrench to verify that all critical fasteners meet the specified torque values, especially around the blade deck, engine mounts, and wheel hubs. Over-tightening can strip threads or warp components, while under-tightening can lead to parts loosening during operation. Refer to the service manual for the exact torque values at different fastener sizes, and apply a suitable thread-locking compound only where recommended. After any maintenance that involves disassembly, recheck all fasteners to confirm they remain within the specified range once components have reassembled and settled. Keeping fasteners tight within the prescribed limits helps preserve vibration resistance and reduces the likelihood of part failure in demanding operating conditions.

The reassembly sequence for the CRAFTSMAN 917.387440 mower requires careful attention to component orientation and torque specifications to ensure reliable operation. Begin by reinstalling the engine mounting grommets and hardware, ensuring each bolt is torqued to the manufacturer’s specified values in a crisscross pattern to promote even pressure. When reattaching the blade drive and spindle assemblies, verify that all spacers and washers are correctly placed and that the blades are balanced to prevent excessive vibration. After securing the deck and linkage components, reattach the electrical connectors with proper polarity and use dielectric grease on high‑voltage connections to prevent corrosion. Conduct a visual sweep to confirm that no tools or loose parts remain in the underside of the deck, then rotate the blade manually to confirm free movement without binding.

Initial start up and safety testing should be conducted with extreme caution, using the proper personal protective equipment and a controlled environment. Before starting, confirm that the blade is clear of any obstructions and that the spark plug boot is firmly connected. Perform a two‑handed ignition sequence as described in the service notes, monitoring for abnormal sounds or smoke. Listen for smooth engine operation at idle, and progressively increase throttle to observe that the engine responds without hesitation or misfiring. Verify that all safety interlocks, such as the blade brake clutch (BBC) and presence levers, engage correctly and halt blade rotation when disengaged. If any warning lights or fault codes are displayed, reference the diagnostic procedure to identify and correct the underlying issue before proceeding with further testing.

Performance verification and adjustments involve a structured assessment of the mowing system and powertrain to ensure optimal output. With the mower on a level surface, measure blade tip speed and verify that it aligns with the specified range for the model; adjust the belt tension if necessary and inspect pulleys for wear or misalignment. Test the transmission engagement and disengagement across the full speed range, noting any slipping or inconsistent response that could indicate belt wear or linkage misadjustment. Check the fuel system for leaks, ensure the air filter is clean, and confirm that the carburetor or fuel injection system delivers the correct mixture under load. Fine tune idle speed, throttle response, and governor settings according to the service documentation, and recheck for proper engine temperature during extended operation. Finally, perform a functional cut test on an unobstructed field to verify consistent cutting height, even ground pressure, and absence of abnormal vibrations, then document all measurements and adjustments for future service reference.

Parts and diagrams

In this section, carefully review the exploded view diagrams and the associated part numbers to verify you are ordering the correct components for the CRAFTSMAN 917.387440. Visually inspect each diagram to identify how parts fit together and to understand the relationship between assemblies and subassemblies. Pay close attention to the orientation of fasteners, gaskets, seals, and spacers, as incorrect placement can lead to improper alignment or loss of performance. When mapping a repair or maintenance task, cross-reference the diagram with the actual machine to confirm that you are working with the exact model configuration and revision level. Document any discrepancies you observe, such as missing hardware or non-original components, to avoid ordering errors and to ensure a successful rebuild. Exploded view diagrams provide a sequential breakdown of components, making it easier to isolate a faulty part and determine the correct removal sequence. Begin at the main housing or drive system and work outward toward peripheral assemblies, noting any interlocking features or alignment pins that must be reinstated during reassembly. Verify that fastener lengths and thread types match the diagram’s specifications, as using an incorrect fastener can compromise integrity or cause interference with moving parts. Use the diagrams as a reference during teardown to prevent accidental damage to delicate components like flywheels, carburetor linkages, and electrical connectors. After completing any repair, consult the exploded views again to confirm that every piece is accounted for and correctly positioned. Part numbers and replacement guidelines are the backbone of effective maintenance. Keep a current list of part numbers for the engine, carburetor, ignition system, and safety components, along with their recommended replacement intervals. When ordering, supply the exact part number, quantity, and any applicable revision or color code to avoid receiving incompatible items. Some parts are sold as kits that include multiple related components, which can simplify ordering but may require additional inspection to ensure all included items fit your machine’s configuration. For wear items such as filters, gaskets, and seals, reference the manufacturer’s service recommendations for replacement frequency rather than relying on visual appearance alone. Maintain a record of replaced parts, including date, running hours, and observed performance, to guide future service planning and budgeting. Where to source genuine replacement parts is critical to preserving performance, reliability, and safety. Start with the authorized CRAFTSMAN parts network or a trusted distributor that lists the exact model number 917.387440 and confirms compatibility with your serial range. When purchasing through secondary channels, request documentation proving genuine OEM sourcing to avoid counterfeit components that may fail prematurely. If you encounter scarce or backordered items, inquire about recommended substitutes or acceptable compatible parts that meet original specifications. For complex assemblies, such as the ignition system or drive mechanism, consult the service literature or manufacturer support resources to ensure the replacement part maintains factory calibration and safety standards. Finally, preserve your receipts and part warranties, and verify the return policy in case a part does not perform as expected after installation.

Warranty coverage and limitations: The Craftsman 917.387440 is provided with a limited warranty designed to protect against manufacturing defects and certain performance failures under normal use. The warranty typically covers parts and workmanship for a defined period from the original purchase date, excluding consumables and wear items. It is important to understand that improper use, lack of routine maintenance, misuse, or alterations can void the warranty, even within the coverage period. Additionally, incidental or consequential damages are generally not covered, and there may be regional variations in what is included, so verify the exact terms specified in the warranty documentation that accompanies the product. When submitting a claim, ensuring that the product was purchased through an authorized retailer and that the serial number and purchase date are readily available will streamline the evaluation process.

Authorized service centers: Warranty service and major repairs should ideally be performed by authorized service centers or factory-certified technicians to preserve warranty validity. Authorized centers have access to official parts, updated service procedures, and technical resources that are not available to uncredentialed repair shops. Before arranging service, confirm the center’s authorization status and whether any diagnostic fees apply if the claim is not covered under warranty. Scheduling and logistics should consider lead times for parts and the availability of appointment slots, especially during peak seasons. For domestic customers, the manufacturer’s customer support can provide a list of approved locations and guidance on how to proceed with a warranty claim.

Documentation and service record keeping: Maintaining thorough service records is essential for warranty compliance and future maintenance planning. Keep copies of purchase receipts, warranty terms, and any correspondence related to service and repairs. For every service event, document the date, the work performed, parts replaced, and the technician’s notes or findings. This documentation can prove invaluable when diagnosing recurring issues or when transferring ownership to a new user, ensuring continuity of coverage and proper maintenance history. If you perform self-repairs beyond basic troubleshooting, retain the service manual references and part numbers used to verify that the work aligns with official guidelines and does not inadvertently affect warranty eligibility.