CRAFTSMAN 917.388590 Service Manual

Overview and scope

The purpose of this service manual is to provide detailed guidance for the maintenance, diagnosis, repair, and safe operation of the CRAFTSMAN 917.388590 outdoor power equipment. It is intended for professional technicians, certified repair personnel, and experienced DIY enthusiasts who possess a foundational understanding of small engine theory, electrical systems, and mechanical instrumentation. This manual emphasizes accuracy, safety, and reproducible results, ensuring that technicians can restore performance while preserving the equipment’s original design intent. Users should approach each procedure with respect for personal protective equipment requirements and the manufacturer’s torque specifications, tool lists, and safety warnings.

Technicians should rely on the manual to identify correct service intervals, replacement parts, and procedure steps that minimize downtime and extend the life of the equipment. The document aggregates troubleshooting tips, calibration procedures, and component-specific instructions, enabling a systematic approach to common failure modes. By following the outlined sequences, technicians can confirm proper operation after assembly and verify that all safety interlocks and control systems function correctly. The manual also serves as a reference for recording maintenance history, parts usage, and any modification notes essential for future service events.

The material herein is organized to support efficient service workflow, from initial fault isolation through final testing. It covers essential areas such as engine and fuel system maintenance, electrical wiring and diagnostics, hydraulic or drive systems if applicable, and preventative maintenance practices. While the manual provides comprehensive procedures, technicians should exercise professional judgment when encountering non-standard symptoms or non-original components, ensuring that any deviations are documented and, where necessary, approved by the equipment’s service policies. This approach helps preserve warranty compliance and maintains the reliability and safety standards expected of Craftsmanship and brand integrity.

Safety information and precautions

Personal protective equipment requirements are essential for preventing injury during maintenance and operation of outdoor power equipment. When inspecting or repairing the CRAFTSMAN 917.388590, always wear safety glasses or goggles to protect against debris, and use hearing protection in environments with elevated noise levels. Gloves should be fitted, durable, and appropriate for the tasks being performed to prevent cuts, burns, or chemical exposure. Depending on the work, a face shield, respiratory protection, and steel-toed boots may be necessary to mitigate specific hazards such as flying particles, dust, or heavy components. Ensure all PPE is in good condition, properly fastened, and readily accessible before beginning any service activity.

Safe operation practices emphasize keeping the work area clean and well-lit, free of clutter, and properly ventilated to reduce the risk of slips, trips, and falls. Disconnect the spark plug wire and remove the battery or power source when performing internal servicing to prevent accidental starting. Use tools correctly and avoid improvising replacements; damaged or worn tools can slip or fail, causing injury. Do not work under the influence of alcohol, drugs, or medications that impair judgment or dexterity. Maintain a calm, methodical approach and verify that all guards and safety devices are in place before restoring power or attempting a test run.

Hazard identification and risk assessment involve recognizing potential sources of danger before work begins. Inspect for fuel leaks, exposed wiring, sharp edges, and hot surfaces that can cause burns or fires. Identify tasks that require lifting or moving heavy parts and employ proper lifting techniques or mechanical assistance to prevent back injuries. Consider weather conditions, such as rain or ice, which can increase slip risks during outdoor maintenance. Establish a plan for emergencies, including knowing the location of fire extinguishers and first aid supplies, and ensure colleagues are aware of the procedure if a hazard escalates. Reassess risks continuously as work progresses and halt operations if conditions become unsafe.

Specifications and tools required

Machine specifications for the CRAFTSMAN 917.388590 are critical for accurate service and safe operation. This model typically features a robust 9.0 to 13.0 horsepower gasoline engine, depending on the production year, paired with a belt-driven cutting deck and a variable-width cutting system. The drive system employs a standard manual transmission or hydrostatic-like control depending on the exact build, and the chassis is designed to withstand typical yard duties such as mowing uneven terrain and minor debris. When documenting the exact specifications for a repair, confirm the engine displacement, horsepower rating, deck width, and pulley ratios from the original serial plate or the official parts manual to ensure compatibility with replacement components. Accurate measurement of belt lengths, blade bolt sizes, and spindle specifications is essential to avoid misfit parts that can cause dangerous operating conditions or reduced performance.

Engine specifications should include the make and model, displacement, compression ratio, lubrication type, and cooling method. Verify the recommended fuel type and the presence of any ethanol tolerance notes, as some units require non-ethanol fuel or specific oil-to-fuel mixtures. Seals, gaskets, and filter types must align with the engine model; using incorrect parts can lead to oil leaks, power loss, or failed starting. For the cutting system, confirm deck height range, blade type, number of blades, and spindle bearing sizes. Electrical components such as safety switches, ignition system, and charging/charging system should be tested according to the service procedures to ensure proper operation and to prevent starting in unsafe conditions.

Required tools and test equipment encompass general mechanical hand tools, specialty wrenches, and diagnostic devices. Essential items include a torque wrench with correct torque specs for blade bolts and spindle fasteners, a pry bar for deck adjustments, and a multimeter for electrical checks. A tachometer may be used to verify engine speed and to diagnose throttle or governor issues. A quality grease gun, lubricant syringes, and a solvent reservoir assist in cleaning and replenishing moving parts. For accurate fuel and oil testing, keep a suitable hydrometer or refractometer on hand to measure oil viscosity and fuel quality. A reputable service manual or OEM parts catalog is invaluable for confirming lock nut sizes, thread pitches, and permissible fastener material when performing disassembly or reassembly.

Recommended lubricants and consumables focus on systems that experience friction, heat, and exposure to the elements. Use high-quality motorcycle or lawn equipment engine oil with the recommended SAE grade and API service rating as specified by the engine manufacturer. For transmission or hydrostatic systems, apply the lubricant recommended in the service bulletin or parts manual, ensuring compatibility with seals and hydraulic hoses. Grease moving joints, spindle bearings, and pivot points with a grease formulated for high-load outdoor equipment. Keep spare air filters, fuel filters, oil filters, and spark plugs on hand to minimize downtime during maintenance cycles. Use appropriate deck and blade lubricants or anti-corrosion sprays on exposed metal surfaces to extend life in humid or salty environments. Always adhere to the OEM oil, fuel, and lubricant intervals to maintain performance and warranty compliance.

The CRAFTSMAN 917.388590 requires careful handling during unpacking to ensure that all components are present and in good condition. Begin by inspecting the carton for any signs of damage during transit, and verify that the model number matches the unit you ordered. Carefully remove the machine and all accessories, laying them out on a clean surface to prevent loss or damage. Check for obvious signs of wear or shipping damage on the engine housing, shield, and handles. If any parts are missing or damaged, contact the supplier or manufacturer before proceeding with any setup to avoid potential safety risks.

Before first use, perform a general inspection to verify that all fasteners and mounting hardware are secure. Tighten any loose screws or bolts to the manufacturer’s recommended torque values, ensuring stability during operation. Inspect the air intake, exhaust, and cooling fins for obstructions or debris that could impede performance or cause overheating. Check the spark plug, carburetor linkage, and fuel system for signs of corrosion or leakage, and address any issues according to the service manual to prevent operating hazards. Ensure that the drive belts, blades, and safety shields are properly aligned and free of cracks or excessive wear. A thorough initial check helps establish a safe baseline for starting the engine and using the equipment responsibly.

The initial setup and factory settings should follow the prescribed sequence to optimize performance and safety. Confirm fuel type and quality, and replace old fuel if necessary to prevent starting difficulties or internal damage. Set the throttle and choke positions according to the manual’s guidelines for cold starts, warming up the engine gradually before full operation. Adjust the blade height and cutting mechanism if applicable, ensuring proper clearance and balanced operation to minimize vibration and wear. Install any required safety devices, such as blade guards and kill switches, and perform a brief function test with the unit secured on a stable surface. By adhering to the factory settings and documented procedures, you establish a reliable baseline for maintenance intervals and long-term reliability of the CRAFTSMAN 917.388590.

During the initial inspection and setup, it is essential to establish a safety routine that protects both the operator and bystanders. Wear protective eyewear, hearing protection, and gloves as part of your standard operating procedure. Keep the workspace well-ventilated and free of flammable materials, and ensure there is adequate lighting to observe all components clearly. Use the manufacturer’s recommended lubricants and replaceable parts to maintain performance and warranty coverage. If you encounter unfamiliar sounds, vibrations, or performance issues beyond minor adjustments, cease operation and consult the service manual or a certified technician for diagnosis to prevent further damage.

Removing and replacing the cutting deck is a foundational procedure for servicing a walk-behind mower. Begin by disconnecting the spark plug wire and ensuring the engine cannot start. Elevate the machine on a stable surface and remove the grass catcher, discharge chute, and any attachments that could obstruct access to the deck. Support the deck with the appropriate stands or supports to prevent it from tipping or shifting during removal. Carefully disconnect all deck-to-frame fasteners, keeping track of hardware and spacers, and note any shield or cable routing to facilitate correct reassembly. Lower the deck slowly, counting the pulleys and belts to ensure alignment remains true when reinstalled. After removal, inspect the deck mounting holes for wear and verify that the deck is free of debris, bent rims, or damaged brackets that could affect performance or safety when reinstalled.

Replacing blades and spindles requires careful attention to safety and precision. Always wear impact-resistant gloves and use a suitable torque wrench to avoid over-tightening mounting bolts. With the deck removed, lock the blade or spindles to prevent rotation using a block, then remove the blade nut, washer, and blade from each spindle. Inspect the blade and spindle for wear, cracks, or warping, replacing any damaged parts with OEM components. When installing new blades, ensure the balance and orientation match the original configuration, and tight blades firmly to the spindle using the correct torque specification. Replace any worn spindle housings or bearings as needed, and apply a light coat of grease to the spindle seals if recommended by the manufacturer. Finally, rebalance the blade set and reinstall the shield and safety systems as they were configured originally, verifying that all blade edges are facing the same direction for proper mulch and dispersion.

Removing and installing belts and pulleys necessitates precise alignment to avoid vibration and belt wear. Begin by removing the belt from the pulleys, noting the belt routing path for accurate reassembly. Inspect belts for cracks, fraying, or glazing; replace any belts that show signs of wear. When removing pulleys, support the components to prevent damage to the deck or spindle shafts, and keep track of any spacers or washers that may affect alignment. Clean all pulleys and shafts before installing new belts, ensuring the belt grooves are free of debris. Route the belt according to the original diagram, ensuring the belt seats fully into every pulley groove without twisting. Apply the recommended belt tension and rotate the pulley by hand to confirm smooth operation before reinstalling the deck and reconnecting power to the unit. After completion, perform a functional test with the safety equipment engaged and confirm that the deck engages smoothly, the blades spin without wobble, and there are no unusual noises indicating misalignment.

Engine oil and filter service is a fundamental maintenance task that protects the engine from excessive wear and helps maintain optimal performance. Begin by ensuring the machine is on a level surface and the engine is cool before draining the old oil. Remove the oil fill cap to vent the crankcase and position an appropriate drain pan under the oil drain plug. After loosening the plug, allow the used oil to completely drain, then reinstall the plug securely and refill with the manufacturer-recommended oil type and capacity. Run the engine briefly to circulate the new oil and check for leaks, then recheck the oil level and top off as necessary. Finally, replace the oil fill cap and dispose of the used oil and filter in accordance with local regulations, ensuring the work area remains clean and free of debris that could contaminate the oil system.

Air filter inspection and replacement is essential to ensure the engine breathes clean air and operates efficiently. Remove the air filter cover or housing, taking care not to damage the seals or gaskets. Remove the filter element and inspect it for signs of excessive dirt, tearing, or oil saturation, which indicate replacement is needed. If the filter is dirty but still intact, clean it according to the manufacturer’s guidelines; otherwise install a new OEM filter to maintain proper airflow and filtration efficiency. Reassemble the housing securely, ensuring the gasket is seated properly to prevent unfiltered air from bypassing the filter. After installation, start the engine and listen for abnormal intake sound, which could indicate an improper seal or an installation issue. Periodic inspection at regular maintenance intervals will help extend the life of the engine and maintain performance under load.

Fuel system inspection and servicing involves checking hoses, clamps, and connections for signs of wear, leaks, or deterioration that could compromise performance or safety. Begin by inspecting the fuel line for cracks, soft spots, or hardening, and replace any damaged sections with OEM components. Check the fuel filter for clogging and replace it if flow is restricted or the element shows signs of contamination. If equipped with a carburetor, remove and clean the carburetor body and jets only using approved cleaners, taking care not to damage gaskets or metering components. Reinstall all components with new seals where applicable, and ensure all clamps are tightened to the correct torque specifications to prevent leaks. After servicing, start the engine and operate at idle and at full throttle to verify smooth fuel delivery and to confirm there are no leaks from the fuel system. Regular fuel system maintenance helps prevent performance issues such as hard starting, rough running, and reduced power output.

Electrical system maintenance

The electrical system of the CRAFTSMAN 917.388590 relies on clean power delivery, properly conditioned charging, and well-insulated connections to perform reliably under varying outdoor conditions. Begin by inspecting the battery for signs of swelling, corrosion at terminals, and readable, intact labels indicating voltage and capacity. Ensure the battery is securely mounted and that mounting hardware remains tight to prevent vibration-induced damage. Measure the battery voltage with a calibrated multimeter, noting that a healthy, fully charged 12-volt lead-acid battery typically reads in the 12.6 to 12.8-volt range when at rest. If voltage is significantly lower, perform a controlled recharge using a compatible charger and monitor for any abnormal heating or fizzing during charging, which would indicate a faulty cell or electrolyte imbalance that requires replacement. Always follow a proper safety protocol, including wearing eye protection and disconnecting the battery before performing any tests that involve potential short circuits or component removal.

Wiring harness integrity is critical for consistent performance of electric-start systems, safety interlocks, and charging circuits. Visually inspect the harness for cracked or chafed insulation, brittle sheath material, or signs of rodent damage that may expose conductors. Trace each major circuit from the battery to its high- and low-power loads, checking for secure connector engagement and proper locking mechanisms. When disconnecting any plug, use minimal force and avoid wiggling to preserve pin alignment and prevent terminal creep. If you discover a damaged wire or connector, replace the affected segment with OEM-rated wiring and connectors, and re-seat all terminals with the appropriate crimping tools to maintain a reliable, vibration-resistant connection. Post-repair, perform a continuity check and insulation resistance test to confirm that there are no inadvertent shorts or breakdowns across insulation materials.

Troubleshooting electrical faults requires a systematic approach to isolate symptoms from root causes. Start with the simplest potential issues, such as blown fuses or tripped safety interlocks, before inspecting more complex components like the charging regulator or ignition module. When diagnosing, verify that battery disconnect switches function as intended and that safety interlocks inhibit engine startup when the operator is not in control. Use a diagnostic scan or solid-state tester to read any fault codes from control modules if available, and document the codes with time stamps for future reference. If a fault persists after verifying power supply and interlocks, inspect the charging system to determine if the alternator, stator, or rectifier is generating adequate current, and check for parasitic drains that could be diminishing battery performance. After repairs or replacements, perform a comprehensive test run under load to ensure that electrical faults do not recur and that starting, lighting, and accessory circuits operate within specified electrical ranges.

Cleaning and corrosion prevention

Cleaning procedures are essential after each use to maintain performance and extend the life of the equipment. Begin by disconnecting the spark plug and removing any fuel from the system if the machine will be stored for an extended period. Use a soft brush to remove loose debris from the exterior surfaces, blades, and cooling fins, taking care not to bend delicate fins or break fragile components. For stubborn grime, wipe down with a cloth dampened in a mild detergent solution, then rinse with clean water and thoroughly dry all surfaces to prevent moisture from seeping into electrical or metal joints. Avoid soaking the engine or exposed electrical connections, and ensure that any solvent-based cleaners do not contact rubber hoses or gaskets, which can deteriorate over time. Regular inspection during cleaning helps identify wear or damage early, allowing for timely maintenance and safer operation.

Rust prevention and protective coatings are critical for maintaining metal components, especially in damp or coastal environments. After cleaning and drying, apply a light coat of quality machine oil or a corrosion-inhibiting spray to exposed metal surfaces, focusing on fasteners, linkage pivots, and tubular frames. Wipe away any excess to prevent dust accumulation and slippage. Pay particular attention to the mower deck, blade spindle, and spring-loaded components where moisture can linger and corrosion can start. If you notice any existing rust, remove it with a non-corrosive rust remover or a fine abrasive pad, then reapply protective coating to seal the treated area. Store treated components in a dry, well-ventilated area to further reduce the risk of rust formation during periods of inactivity.

Storage recommendations emphasize keeping the machine in optimal condition when not in use. Choose a dry, climate-controlled location away from extreme temperatures and humidity fluctuations, which can accelerate corrosion and degrade lubricants. Before storage, run the engine briefly to distribute lubrication, then seal the fuel system by draining the tank or adding a year-round stabilizer per the approved manual procedures to prevent fuel degradation. Remove or disconnect electrical connections where applicable and cover the equipment with a breathable, non-abrasive cover to prevent dust buildup while allowing moisture to escape. Periodically inspect stored units for signs of rust, pests, or condensation, and reapply lubrication or protective coatings as needed to maintain readiness for the next use. Implementing a consistent storage routine helps preserve performance and reduces the likelihood of corrosion-related failures when you resume operation.

The Craftsman 917.388590 mower combines a compact footprint with reliable performance, but like any power equipment, it can exhibit a range of symptoms that point to specific failures. Common symptoms include a lack of spark, no starting, rough running, misfires, excessive exhaust, or reduced cutting efficiency. Several underlying causes may be responsible, such as fuel issues (old or contaminated fuel, clogged fuel filters, or carburetor varnish), ignition problems (faulty spark plug, ignition coil, or wiring), air intake obstructions (dirty air filter or intake hoses), or mechanical wear (damaged valves, worn piston rings, or a loose flywheel key). It is essential to document the exact conditions under which the symptom occurs, including engine load, ambient temperature, and recent maintenance, to narrow down the probable cause efficiently. Understanding these common symptoms helps technicians prioritize diagnostic steps and minimize downtime for the user.

When addressing a symptom such as the engine failing to start, begin by verifying basic safety and serviceability: ensure the spark plug is clean and properly gapped, confirm the ignition switch and safety key are functioning, and check for adequate fuel presence with fresh, ethanol-free fuel if possible. Inspect the fuel system for leaks or cracks in lines and verify that the carburetor is receiving fuel and not clogged by varnish or debris. A no-spark condition may indicate a faulty ignition coil, a damaged kill switch circuit, or a failed spark plug wire. If the engine is cranking but not firing, focus on the fuel delivery path, including fuel filter cleanliness and carburetor fuel metering, as well as potential air intake restrictions. Each diagnostic step should be accompanied by a clear confirmation test and visual inspection to avoid misdiagnosis.

For a mower exhibiting rough running or misfires, evaluate spark plug condition, verify proper carburetor adjustment, and check for vacuum leaks around the intake manifold and carburetor boots. Inspect the air filter for excessive dirt or damage, replace if necessary, and ensure the air intake is free from obstructions. Fuel-related issues require checking fuel quality, fuel filter, and the operation of the primer bulb if equipped. If fuel is contaminated or if ethanol blends are used beyond the recommended limit, drain and replace with appropriate fuel. In the event of excessive exhaust or smoke, examine oil levels and possible oil intrusion into the combustion chamber, as well as worn piston rings or an exhaust valve leak, and perform further compression testing if indicated by observed symptoms.

The step by step diagnostic flowchart follows a logical sequence designed to quickly isolate faults while preserving safety and equipment integrity. Start with safety checks, including disconnecting spark plug cap before inspection. Move to fire and fuel verification: confirm spark, fuel presence, and carburetor operation. If the engine fails to spark, test the ignition coil resistance and examine the kill-switch wiring for continuity or short circuits. If spark is present but fuel seems inadequate, test the carburetor’s fuel inlet flow and inspect the fuel filter; clean or replace components as necessary. If compression tests show low results, proceed to inspect valves and assess mechanical wear, including drive components that could affect timing and compression. Document all measured values and behavior at each stage to build a traceable maintenance record.

Replacement parts for common failures are selected to restore performance with reliability and safety in mind. When addressing ignition problems, replace the spark plug with a manufacturer-recommended grade and verify the ignition coil and wiring are within specification before reinstalling. For fuel system issues, use a high-quality fuel filter matched to the engine’s flow requirements, and consider replacing the carburetor gaskets or seals if leaks are detected. Air intake components, including the air filter and pre-cleaner, should be replaced with OEM or equivalent parts that meet filtration efficiency standards. If mechanical wear is identified, plan for the replacement of seals, rings, or gaskets, and evaluate whether timing components require attention. Maintain a spare parts list with compatible carburetor kits, gaskets, and ignition components to expedite future repairs and minimize downtime for the user.

Routine maintenance schedule

Daily maintenance tasks are essential for keeping outdoor power equipment in reliable working condition and extending its service life. Begin each use by performing a quick visual inspection for loose fasteners, damaged guards, or fuel leaks, and address any issues before operating the machine. Check fluid levels, including engine oil, coolant (if applicable), and fuel, ensuring there is no contamination or unusual odor. Wipe down exterior surfaces to remove dirt, dust, and debris that could hinder cooling or airflow, and inspect the air filter housing for obstructions that could compromise engine performance. After operation, clean the air intake area and check for built-up grass or debris that could impede cooling fins or mufflers, paying attention to concealed heat sinks and cooling ducts. Maintaining a clean surface not only improves efficiency but also reduces the risk of overheating and component wear over time.

Weekly maintenance tasks focus on improving longevity and preventing performance decline. Remove and inspect the air filter; if it is dirty, replace it or clean it according to the manufacturer’s guidelines, making sure the seal is intact to prevent unfiltered air from entering the engine. Inspect spark plugs for signs of wear, fouling, or gaps, and replace them if necessary to maintain reliable starting and smooth idle. Check the fuel system for leaks, cracks in hoses, and loose clamps, tightening or replacing parts as needed to prevent fuel loss and fire hazards. Lubricate moving linkages, cables, and pivot points with the recommended lubricant to reduce friction and wear, and ensure that all belts show proper tension without slipping. Perform a preliminary belt and pulley inspection for wear or cracks and adjust or replace parts to maintain consistent power transmission.

Monthly maintenance tasks delve deeper into engine and safety systems to prevent cascading failures. Drain and replace engine oil if required by the service interval and replace the oil filter if your model employs one, ensuring the engine fills to the correct level with the appropriate grade. Replace the fuel filter to prevent contaminants from reaching the carburetor or injection system, and inspect the fuel lines for hardening or cracking. Inspect cooling fins and radiators (if water-cooled) for dirt, grass, or leaves, and clean thoroughly to maintain proper heat dissipation. Check the battery condition, terminals, and wiring for corrosion or loose connections, and perform a load test if applicable to avoid unexpected starting failures. Verify safety systems, such as blade engagement interlocks or safety switches, are functioning correctly, and replace any damaged components before operating the unit again.

In addition to these scheduled tasks, record-keeping is an important part of routine maintenance. Maintain a log of dates, hours of operation, and any parts replaced or repairs performed, which helps identify recurring issues and supports warranty considerations. Use manufacturer-approved lubricants and replacement parts to ensure compatibility and performance, and always consult the owner’s manual or a certified service professional for tasks that require specialized tools or expertise. Adhere to safety guidelines, disconnect the spark plug or battery as appropriate before performing maintenance, and wear appropriate personal protective equipment to reduce the risk of injury. By following these practices, you’ll keep your outdoor power equipment operating safely and efficiently for years to come.