CRAFTSMAN 917.273980 Service Manual

Preparing for service and maintenance

Before beginning any service or maintenance on the CRAFTSMAN 917.273980, ensure the power equipment is disconnected from all power sources and secured to prevent accidental startup. Remove the battery or ensure the unit is unplugged from any electrical outlet, and inspect the surrounding area for any hazards such as fuels, solvents, or sharp edges. Gather the necessary tools and safety gear listed below to create a controlled work environment that minimizes risk of injury or further damage to the machine. Establish a clear workspace with good lighting, stable surfaces, and a place to organize fasteners and components as they are removed.

Having the right safety gear is essential for protecting against cuts, burns, and chemical exposure. Wear cut-resistant gloves, safety glasses or a face shield, and sturdy footwear with non-slip soles. If there is potential for fuel or oil exposure, have absorbent material and a containment tray on hand. A bar or socket set, screwdrivers of various sizes, pliers, a torque wrench, and a clean magnetic tray for small parts should be readily accessible. Keep a fire extinguisher nearby when working with fuel-powered components, and have a notebook or digital device to record observations and any part numbers encountered during the inspection process.

Initial inspection and diagnostic planning require a systematic approach to assess the mower’s condition and identify failing components. Begin with a general visual inspection, noting any signs of oil leaks, damaged hoses, warped or cracked plastics, and unusual wear on belts or pulleys. Check the spark plug, air filter, and carburetor (if applicable) for cleanliness and proper gaps, and verify the presence of fresh fuel and correct oil levels. Create a diagnostics plan that prioritizes safety-critical systems such as the drive mechanism, blade assembly, fuel system, and ignition. Document routine maintenance items and potential failure modes to guide the repair steps and ensure nothing is overlooked during disassembly and reassembly.

Next, perform a quick functional check where safe to do so, observing any abnormal noises, vibration, or smoking. If the unit has a blade brake or safety interlocks, test these features in a controlled manner to confirm they are operating as designed. Record all telemetry and observations to establish a baseline for comparison during subsequent repair stages. Use the gathered data to determine which components require cleaning, adjustment, replacement, or further diagnostic testing, ensuring that your plan aligns with the manufacturer’s specifications and torque values. By maintaining a methodical, documented approach, you enhance repair accuracy, reduce troubleshooting time, and help ensure the service will restore reliable performance to the equipment.

Craftsman lawn equipment requires careful disassembly to access critical components while maintaining safety and ensuring accurate reassembly. Begin by powering down the unit, removing the spark plug wire, and disconnecting the battery if applicable to prevent accidental starting. Wear appropriate eye protection and gloves, and work on a clean, stable surface with tools organized to reduce the risk of lost fasteners. Guards and shields protect you from moving parts and flying debris, so they must be removed only after the engine is cool and the cutting area is immobilized. Carefully label and photograph fastener placements as you remove guards to simplify reinstallation and preserve proper alignment during maintenance. Removing guards and shields involves identifying all mounting points that secure the protective assemblies to the mower chassis. Start with the discharge chute and deck side guards, loosening the retaining bolts and setting fasteners aside in labeled containers. Inspect the shields for any cracks or deformation that could compromise safety and replace damaged parts before continuing. When detaching these components, avoid bending or stressing adjacent wiring or hoses, which can create future trouble. After removal, store guards in a clean, dry location to prevent wear or corrosion that could affect fitment during reassembly. Accessing the cutting deck and spindle assemblies requires removing any obstructing components such as the belt covers, pull start housing, and any decorative shrouds. With the deck exposed, rotate the blade slowly by hand to check for freedom of movement and verify that the blade is not contacting the spindle housing. Remove the blade with the correct wrench or socket, noting the orientation and sharpness for eventual sharping or replacement. Inspect the spindle assemblies for play, listen for grinding sounds, and check for oil leakage around the seals. If spindle bearings show wear, plan for bearing replacement using manufacturer-specified parts and torque values. After the deck is fully accessible, remove the belt from the pulleys, taking care not to twist or stretch it, and label the belt routing for reinstallation. Removing fuel system components requires safely decoupling all lines and fittings associated with the carburetor, fuel pump, and tank. If the unit uses an external fuel line, detach it at the quick-connect or barb fittings with minimal force to avoid cracking connections. Cap or seal open fuel ports to minimize air exposure and prevent contamination. Inspect fuel lines for cracks, stiffness, or soft spots and replace any compromised sections. When removing the carburetor or fuel-related components, document the position of clamps, springs, and linkages to ensure proper reassembly. Reassemble the system by following reverse order, ensuring all connections are secure and free of leaks, and perform a cautious test after maintenance to verify correct operation and safety compliance.

Engine and fuel system service

Engine model identification begins with confirming the specific engine installed in the equipment, as models and configurations can vary within the same machine family. Locate the engine model number and serial information on the engine nameplate or on a tag affixed to the blower housing or valve cover. Cross-reference the model number with the manufacturer’s service documentation to verify correct parts, torque specs, and procedures. Document the identified model for future reference, including any recent maintenance history, symptoms observed, and operating hours. Accurate identification ensures that replacement parts and service steps align with the exact engine configuration, reducing the risk of improper maintenance.

For fuel system inspection and servicing, start by inspecting the fuel supply for contamination, varnish buildup, or degraded fuel lines. Check the fuel shutoff valve, fuel lines, and connections for leaks or cracks, replacing any compromised components. Drain and replace old fuel if it has been stored for an extended period, and use fresh gasoline blended to the recommended octane and ethanol content. Inspect the fuel filter or screen for clogs and clean or replace it as necessary, ensuring unobstructed fuel flow. When servicing the carburetor or fuel delivery system, follow precise disassembly and reassembly steps, take note of the order of gaskets and seals, and perform fuel system tests after reassembly to confirm proper operation and no leaks.

Air intake and exhaust considerations require inspecting the air filter for media damage, excessive restriction, or oil contamination, and replacing it if needed. Ensure the air intake path is clear of debris, and check the carburetor boot or intake gaskets for cracks or leaks that could cause unmetered air to enter the system. Clean any dirt or oily buildup from the muffler and exhaust outlet, and inspect the muffler for signs of deterioration or rattling that may indicate internal damage. When reinstalling components, verify that clamps and hose connections are secure and that the air intake system provides a consistent, obstruction-free path for air to the combustion chamber.

Ignition system inspection and replacement procedures begin with checking the spark plug for wear, fouling, or improper gap. Remove the spark plug and inspect the electrode condition, insulator cleanliness, and measured gap; replace the plug if it shows excessive wear or deposits. Test the ignition coil resistance and wiring continuity according to the engine's specifications, looking for any signs of damaged insulation or loose connections. If ignition timing or spark quality is suspect, perform a controlled start-up test in a safe environment and observe for misfires, backfiring, or failure to start. When replacement is necessary, use manufacturer-approved ignition components and torque fasteners to the specified values, re-check clearances, and perform a test run to confirm reliable ignition and stable engine operation.

Electrical systems and troubleshooting

The electrical system in the CRAFTSMAN 917.273980 combines safety interlocks, power distribution, and charging functions to ensure reliable operation of the lawn tractor. Begin by visually inspecting the wiring harnesses for signs of wear, chafing, or loose connections. Carefully trace the harness routing to confirm that wires are protected from moving parts, heat sources, and sharp edges. When reassembling or adjusting, use the original routing guides and clamps to maintain correct paths and prevent future damage. A clean, intact harness is essential for accurate diagnostics and safe operation, so replace any damaged sections with OEM-approved wiring and connectors. Always disconnect the battery before inspecting or working near electrical components to avoid accidental shocks or shorts.

Wiring harness identification and routing requires familiarity with the harness layout and color-coding used in this model. Start by mapping the main harness from the battery to the sub-harnesses powering the controls, safety switches, and charging circuit. Use a service manual diagram to confirm pinouts and connector orientations, ensuring that each connector mates securely and is fully seated. When routing new or replacement wiring, keep leads away from the fuel system, exhaust, and rotating components. Securing wires with appropriate ties and clips helps maintain consistent tension and prevents wear due to vibration or movement. After any routing work, perform a continuity check and inspect for potential shorts or pinched conductors during a functional test of the ignition and safety systems.

Safety interlock system checks must verify that the operator presence, PTO, and seat/ride safeguards function correctly before the engine can start or run certain accessories. Begin by testing each switch individually with a multimeter or a suitable diagnostic tool to confirm expected resistance or open/closed states in all modes. With the engine off, confirm that the interlocks prevent cranking when any switch is disengaged or improperly engaged, and that normal starting occurs only when all requirements are satisfied. Repeat checks with the engine running to verify that interlocks properly disable dangerous operations if a switch is activated unexpectedly. Document any fault codes or abnormal readings and trace the corresponding circuits to their sources, replacing any faulty switches or connectors as needed. Regular testing of the interlock system helps prevent accidental operation and enhances overall safety.

Charging system and battery maintenance cover the alternator/charging circuit, battery condition, and related wiring. Inspect the battery for clean terminals, secure mounting, and no signs of swelling or leakage. If corrosion is present on terminals, disconnect the negative terminal first, clean with a non-abrasive brush and a baking soda solution, rinse, dry, and re-tighten to the recommended torque. Inspect the charging lead and alternator connector for damage, corrosion, or loose pins; replace compromised components with OEM parts to maintain proper charging voltage output. Measure battery voltage with the engine off and then with the engine running to verify that the charging system maintains a stable voltage within the specified range. If undercharging or overcharging is detected, inspect the regulator, wiring harness continuity, and the flywheel area for grounding issues, then address any compromised components. Regular battery maintenance and charging system checks help prevent startup problems and extend the life of electrical components.

Throughout electrical troubleshooting, prioritize safety by disconnecting power sources before handling connectors, and by using insulated tools when probing live circuits. Maintain a clean workspace free of moisture and conductive debris to reduce the risk of shorts. When in doubt, refer to the OEM service diagram for exact wire colors and connector shapes, and replace any questionable parts with authentic components to preserve system integrity. With careful inspection, methodical testing, and proper part replacement, you can identify and resolve electrical faults efficiently, keeping your CRAFTSMAN 917.273980 performing at peak reliability.

The cutting deck and drive system are closely linked in maintaining mowing efficiency and machine longevity. Proper deck level and blade alignment ensure consistent cutting height, prevent scalping, and minimize vibration that can accelerate wear on bearings and spindles. Begin by inspecting the deck for any distortions, ensuring the mounting holes are not elongated, and confirming the deck is level from front to back and side to side. Use a reliable deck leveling tool or a straightedge placed across the blade edges to verify evenness, and adjust the deck mounting nuts in small increments to achieve uniform height across all cutting positions. After leveling, check blade alignment by measuring tip-to-spindle distance at multiple points around the blade circumference; misalignment can cause uneven cuts and increased blade wear. Regularly inspect spindle housings for looseness or play, as excessive movement can lead to blade wobble and accelerated component fatigue. A properly leveled and aligned deck not only improves cut quality but also contributes to safer operation by reducing vibration transmission to the operator and chassis.

Blade installation and sharpening procedures are critical for maintaining cutting performance and engine load. When removing and reinstalling blades, ensure the ignition is off and the spark plug wire is disconnected to prevent accidental starting. Use the correct blade type and part number recommended by the manufacturer, and ensure the blade is mounted with the correct orientation so the cutting edge faces the direction of rotation. Remove any burrs with a fine sharpening stone or file, taking care to maintain a consistent edge angle across all cutting surfaces. Balance the blades after sharpening or replacement to minimize vibration; a high-speed balance wheel or professional blade balancer can help verify even weight distribution. Replace dull or chipped blades promptly, as they demand more engine power, reduce cut quality, and can cause motor overheating over extended use. Always re-check blade tightness after sharpening or replacement to prevent loosening during operation.

Drive belt inspection and replacement procedures protect the drive system from slip, wear, and loss of power transmission. Periodically inspect belts for cracking, glazing, fraying, or missing ribs, and replace any belt that shows signs of deterioration. Check belt tension according to the manufacturer’s specifications, as excessive slack can slip and wear prematurely, while overtightening can strain pulleys and bearings. When installing a new belt, route it according to the diagram on the machine or in the service manual, ensuring it sits properly in all pulley grooves and that the belt is not twisted. After replacement, run the engine at a low speed and listen for abnormal noises or vibrations, and perform a manual test by engaging the ground drive to confirm smooth engagement and consistent belt tracking. For variable-speed or hydrostatic drives, consult the specific procedure for belt alignment and tension to prevent belt wear and trajectory deviations. Regular belt maintenance helps preserve fuel efficiency, power transfer, and overall drive performance.

Transmission and drive system checks encompass a comprehensive evaluation of how power is transmitted from the engine to the cutting deck and wheels. Begin with a visual inspection of the transmission case for leaks, cracks, or loose mounting hardware, and verify that cooling fins are free of debris. Check all drive linkages, pivot points, and tensioners for excessive play or wear, replacing worn components as needed to maintain precise control. For belt-driven systems, inspect pulleys for grooves or corrosion and ensure belt alignment is true with minimal lateral deflection. In hydrostatic or automatic transmissions, monitor fluid levels and condition; dark, burnt, or metallic-smelling fluid may indicate internal wear requiring professional service. Perform a road test or simulated load run to evaluate smooth engagement, acceleration, and braking response, noting any slipping or unusual noises that could indicate a misadjusted drive system. Regular, thorough transmission checks help extend service intervals, improve mowing efficiency, and reduce the likelihood of unexpected breakdowns.

Cooling and lubrication systems

The cooling system on the CRAFTSMAN 917.273980 is designed to maintain optimal operating temperatures under varying load conditions. Start with a visual inspection of all cooling components, including the radiator, hoses, clamps, and fan shroud, to identify cracks, leaks, or wear. Check coolant level in the reservoir or cooling bottle and confirm that there are no signs of contamination such as oil slicks or debris. When flushing, ensure the engine is cool and the drain is opened slowly to avoid spillage. Use the recommended cleaning solution and distilled water, and perform a thorough rinse until the fluid runs clear, then reassemble with fresh coolant to the proper specification. Periodically inspect the coolant hoses for hardening, bulging, or soft spots, replacing any deteriorated hose sections to prevent overheating or sudden coolant loss during operation.

Lubrication points and schedules are critical for extending the life of moving parts and ensuring smooth operation. Identify all lubrication points, including the pivot points on the cutting deck, drive linkage, and auxiliary equipment. Apply the recommended lubricants in the exact quantities and intervals specified by the manufacturer, taking care to wipe excess lubricant away from belts and pulleys to prevent slippage or debris attraction. Create a maintenance log that records each lubrication event, noting the date, time, and any observed changes such as increased stiffness or play in the linkages. Regularly inspect grease fittings and replace worn seals or gaskets to maintain a clean, sealed system and to minimize the ingress of dirt that can accelerate wear. Follow a cautious approach around hot engine surfaces and moving parts, allowing components to cool before applying lubrication to avoid burns or lubricant breakdown from heat.

Oil type specifications and changes require strict adherence to the recommended grade and viscosity. Use only the oil type specified in the service manual for the engine and accessory gear systems, and verify the oil capacity after each change. When performing an oil change, drain the used oil completely, replace the oil filter if equipped, and ensure the drain plug is torqued to the manufacturer’s specification to prevent leaks. After filling, run the engine briefly to circulate the new oil, then recheck the dipstick or sight glass to confirm the correct level. Dispose of used oil and filters in accordance with local environmental regulations, and avoid mixing oils of different viscosities or brands, as this can compromise lubrication performance and engine reliability. Periodic checks should include electrolyte levels in any hydraulic reservoirs and the integrity of seals and gaskets to maintain clean lubrication pathways and prevent contamination of the oil supply.

Diagnostics and error codes

Interpreting service indicators requires careful observation of the machine’s indicator lights, audible alerts, and any displayed error codes. Begin by noting the exact sequence of LED flashes or steady states, as these patterns map directly to fault categories such as ignition, fuel delivery, electrical circuits, or safety interlocks. If the equipment provides a digital display, document the numeric or alphanumeric codes shown during startup or when the fault occurs. Cross-reference these indicators with the typical code library for the model to determine whether a code denotes a recoverable condition or a fault requiring component replacement. When indicators are ambiguous, perform a controlled power cycle to confirm whether the fault persists, as transient faults can sometimes reset after a reset. Always ensure the unit is placed in a safe state before inspecting any indicators to prevent unrelated signals from masking the true problem.

Common fault scenarios and remedies require a methodical approach to avoid unnecessary part replacement. For fuel-related issues, verify that the fuel is fresh, correctly mixed if applicable, and free of water or contamination. Inspect the fuel line, filter, and carburetor for signs of clogging, cracks, or leaks, and replace components as needed. Electrical faults often present as intermittent starting problems or loss of power; check fuses, wiring harness connections, and battery health, ensuring terminals are clean and secure. If the unit fails safety interlock checks, confirm that the control levers, blades, and seat switches are correctly engaged or bypassed only with proper procedural safeguards. For ignition problems, test the spark plug for fouling or incorrect gap, and verify the ignition coil and associated wiring are within specification. In all cases, replace compromised parts with OEM equivalents and re-test the system after each corrective action to ensure the fault is resolved before returning the machine to service.

Reassembling components in proper sequence requires meticulous attention to the order in which parts were removed or displaced during disassembly. Begin by laying out all fasteners, spacers, and hardware in labeled containers to prevent mix-ups. When reattaching major assemblies, align mating surfaces carefully and begin threading fasteners by hand to avoid cross-threading. Use a torque wrench to tighten bolts to the manufacturer’s specified values, following a gradual, crisscross pattern to ensure even clamping force. After securing each subassembly, verify that moving parts operate freely without binding, and recheck any belts or chains for proper tension as described in the service notes. Document any deviations from the original layout and replace worn components before proceeding to the next assembly step.

Safety checks before startup are essential to prevent injury and equipment damage. Inspect all guards, covers, and safety switches to confirm they are secure and functional. Check the hydraulic or fuel systems for leaks, ensuring that fittings are tight and hoses are free of cracks or signs of wear. Verify that all electrical connections are clean, dry, and properly insulated, and that the battery is fully charged if applicable. Each moving part should rotate smoothly without excessive play, and all warning decals must be legible and in place. Before applying power, ensure the service area is clear of ignition sources and that bystanders maintain a safe distance. Finally, perform a functions test on controls at idle to confirm expected response before full operation.

Performance testing and adjustments involve a structured approach to validate the machine’s operation under typical load conditions. Start with a brief idle run to observe for abnormal noises, vibrations, or overheating. Gradually test power delivery, ensuring the engine or motor maintains consistent RPM and torque across the rated range. Measure emitted exhaust, temperature, and any sensor feedback to confirm they stay within specification. If performance deviates, adjust calibrated controls in small increments and re-test to avoid overcorrection. Document all adjustments and residual readings, then perform a field test under realistic workload to confirm reliability. If discrepancies persist, consult the service manual’s troubleshooting guide to identify root causes and plan corrective actions.

The maintenance schedule for the CRAFTSMAN 917.273980 is designed to keep the outdoor power equipment performing reliably and safely across seasonal use. Establish a routine that aligns with the operating hours and environmental conditions your machine experiences. Begin with a baseline inspection after each use, checking critical systems such as the engine, fuel system, and lubrication points. Document any deviations or unusual sounds, vibrations, or performance changes to establish a running history that informs future service decisions. Adhering to a structured schedule helps prevent unexpected breakdowns and extends the overall lifespan of the unit.

Routine maintenance intervals should be determined by a combination of running hours and calendar time. For most environments, perform a light inspection after every 8 hours of operation, a more thorough check every 25 hours, and a comprehensive service every 50 hours or at the end of a mowing season, whichever comes first. The light inspection focuses on fuel, oil levels, air filter condition, and quick visual checks of belts and pulleys. The 25-hour interval should include air cleaner maintenance, spark plug condition check, and a general belt tension assessment. At the 50-hour mark, replace consumables such as the air filter and spark plug as indicated by wear or fouling, inspect the cooling system, and verify all fasteners are tightened to specification. Adapting these intervals to heavy-duty use or harsh environments is essential, and increasing the frequency of checks in such conditions helps maintain optimal performance.

Recommended spare parts and lifespan indicators are integral to minimizing downtime and ensuring safe operation. Keep a stock of essential items like air filters, fuel filters, spark plugs, and oil that match the OEM specifications for the 917.273980. Lifespan indicators include visible wear on belts, signs of oil or fuel leaks, and deterioration of hoses or clamps. Replace belts showing glazing, cracking, or significant wear immediately to prevent drive failure. Monitor the condition of the starter rope, recoil assembly, and cooling fins for signs of fraying or obstruction, and replace as needed. Use OEM or equivalent quality parts to maintain compatibility with the engine and mowing deck systems, and document all parts replacements with date codes to track maintenance history for future service planning.

Routine lubrication and cleaning are also critical in the maintenance plan. Periodically clean the cooling fins and air intake to prevent overheating, and lubricate pivot points and attachment interfaces with the recommended lubricants. Ensure the fuel system remains clean by using fresh, high-quality gasoline and a fuel stabilizer if storing the machine for extended periods. Keep the battery terminals clean and tight, and inspect the charging system to confirm proper voltage output. By combining correctly timed inspections, appropriate spare parts management, and disciplined lubrication practices, you maintain safe operation and consistent cutting performance while reducing the risk of unexpected downtime.

Lockout tagout procedures are critical for ensuring that the power tools and equipment within the CRAFTSMAN 917.273980 have no energy source active during maintenance or repair work. Before beginning any service, verify that the machine is unplugged from its power supply and that any stored energy in capacitors, springs, or other energy storage devices is safely discharged. Apply a visible lockout device and tagging system that clearly communicates that maintenance is in progress and who is responsible. Do not attempt to bypass or defeat locking devices, as this can lead to sudden energization, serious injury, or damage to the tool. Documentation of the lockout process should be retained in the service log, including the date, technician name, and the specific energy sources isolated. When multiple technicians are involved, coordinate a shutdown sequence to ensure a controlled and safe reset, and only restore power after all personnel are clear of the work area and all tools are accounted for. Prior to energizing the equipment for testing, perform a thorough inspection to confirm that guards, shields, and safety interlocks are reinstalled correctly and that no tools or debris remain in the operating paths.

Hazardous material handling and disposal procedures are essential for safely managing any consumables or fluids encountered during service, including oils, fuels, solvents, and cleaning agents. Always consult the manufacturer’s material safety data sheets (MSDS) for the specific chemical composition and associated hazards of each substance you handle. Use appropriate personal protective equipment such as gloves, goggles, and, when necessary, a respirator to minimize exposure risk. Store hazardous materials in clearly labeled containers that are resistant to leaks and compatible with their contents, and keep them in a dedicated, ventilated area away from ignition sources. When transferring fluids, use closed systems and secondary containment to prevent spills, and have routine spill response supplies readily available. Dispose of waste materials in accordance with local environmental regulations and recycling programs, documenting each disposal incident to maintain compliance. After completing work, thoroughly clean the work area to prevent residue buildup and ensure safe operation for the next user.