EXMARK LAS28KA724 Service Manual
The Exmark LAS28KA724 is a commercial-grade zero-turn mower designed for professional lawn care and high-usage environments. This model features a compact footprint with a robust cutting system and a durable chassis to withstand frequent operation under demanding conditions. Key specifications include a high-torque engine, hydraulic drive system, and precise steering controls that enable tight cornering and efficient mowing patterns. Electrical components are integrated to support dashboard diagnostics and quick fault identification, while the cutting deck offers adjustable height settings to accommodate varying turf conditions. Proper understanding of these baseline specs is essential for accurate maintenance and safe operation within a professional fleet context.
Engineered for reliability, the LAS28KA724 incorporates a heavy-duty air filtration system, a sealed cooling pathway, and reinforced drive components to minimize downtime. The fuel system is designed to handle commercial fuel loads with attention to emission standards and fuel efficiency. The hydraulic system provides smooth traction and lift capabilities for the cutting deck, with pressure relief and filtration designed to prevent contamination from particulates. The chassis and roll-over protection are engineered to maintain rigidity under vibration and load, supporting long working hours without compromising operator safety. Familiarity with these features supports proactive maintenance planning and reduces the likelihood of unexpected failures in the field.
Overview of Exmark Las28ka724 Service Manual
The manual begins with a concise overview of machine specifications, including engine type, capacity, cutting width, deck lift mechanism, and hydraulic circuit layout. It presents critical service intervals, recommended lubricants, and the standard tools required for routine maintenance. Understanding these baseline details helps technicians prioritize tasks, schedule preventive maintenance, and track wear patterns across components. The document also outlines common system interrelationships, such as how the hydraulic lift interacts with deck height adjustments and how electrical diagnostics correlate with sensor inputs. This foundational knowledge enables accurate diagnosis and efficient repair planning in a professional maintenance setting.
Safety warnings and basic training prerequisites are presented to establish a protective framework for technicians and operators. The manual emphasizes proper lockout/tagout procedures, personal protective equipment, and safe fuel handling practices to prevent injury and environmental exposure. It also outlines the required qualifications for servicing the machine, including familiarity with hydraulic systems, electrical schematics, and engine fundamentals. Operators are instructed on safe starting and shutdown procedures, as well as routine inspection checklists before each shift. By adhering to these safety guidelines, maintenance work can be performed with reduced risk, ensuring both technician welfare and operational reliability of the LAS28KA724 in professional service environments.
Tools and Service Environment
When performing maintenance or repair on the EXMARK LAS28KA724, begin by assembling the essential hand tools, diagnostic gauges, and specialty equipment required for safe and effective service. A calibrated torque wrench is critical for reassembly to the manufacturer’s specified torque values, ensuring fasteners maintain proper clamping force without overtightening. A metric and SAE socket set, combination wrenches, and hex key sets should cover the common fasteners found on mower chassis, deck, spindle housings, and fuel system components. A digital multimeter with appropriate probe tips is necessary for checking electrical circuits, sensor readings, and continuity, while a suitable scan tool or diagnostic adapter can aid in interfacing with onboard electronics if the model includes electronic controls. It is prudent to have a magnetic tray or labeled bins to organize small parts and fasteners, along with labeled rags, degreaser, and disposable shop towels to manage lubrication and cleaning tasks without cross-contamination.
In addition to general hand tools, maintain a set of specialty gauges and measurement devices tailored to outdoor power equipment. A micrometer or caliper helps measure critical dimensions on components such as the blade spindle, pulley hubs, and brake surfaces with high precision. A fuel pressure gauge and vacuum gauge can be employed when troubleshooting the fuel delivery system and vacuum-operated controls. For deck and cutting components, rely on a straightedge and feeler gauges to verify alignment, flatness, and proper blade clearance. A torque-angle gauge may be required for reassembly of components that specify not only torque but also angular tighten sequences. Ensure you have a quality lubrication syringe and grease coupler for controlled lubrication of pivot points and bearings, reducing downtime caused by over-application or under-lubrication.
Service environment setup and safety considerations
Establish a clean, well-lit work area with a stable, level surface to prevent tipping or shifting of heavy equipment during service. Use a dedicated workbench or stand that can support the machine’s weight and dimensions, and ensure the environment is free of clutter to minimize the risk of dropped tools or misplaced fasteners. Implement a controlled ventilation strategy if any solvents, degreasers, or fuel vapors are present, and keep a fire extinguisher rated for flammable liquids readily accessible. Wear appropriate personal protective equipment, including safety glasses or a face shield, cut-resistant gloves, and hearing protection when operating or testing powered components. When disconnecting the battery or servicing electrical systems, remove metallic jewelry and follow proper lockout/tagout procedures to prevent accidental energization.
Organize the service area to mirror the vehicle’s or machine’s workflow, minimizing movement between tasks and reducing cross-contamination of oil, fuel, and coolant. Use labeled containers for disposing of used oil, filters, and any contaminated wipes, and follow local environmental regulations for disposal. Ensure that all tools are accounted for before power is applied and that the machine is securely supported with jack stands or a lift if access to the underside is required. Finally, verify that a clear drain and exhaust path exists when running the engine, and keep spectators and bystanders at a safe distance during testing to prevent injury in case of unexpected disassembly or debris release.
Maintenance Schedule and Preventive Care
The EXMARK LAS28KA724 is designed to operate reliably when routine maintenance is performed on a consistent schedule. Establishing a daily maintenance routine helps identify wear, leaks, or degraded performance before they lead to costly repairs or unsafe operation. Begin each use by conducting a quick visual inspection of the entire unit, checking for loose fasteners, damaged guards, or obvious signs of hydraulic or fuel leaks. Verify that all safety devices are intact and functional, including seat switches, blade brake, and safety interlocks. Ensure that the battery connections are clean and tight, and that the fuel and oil levels are within the recommended ranges before starting the machine.
Daily maintenance tasks should also include checking tire pressure if applicable, inspecting the air intake and cooling system for debris, and wiping down surfaces to remove dust and grass clippings. Clean or replace the air filter as needed according to the operating environment, and ensure the cooling fins and belt guards are free from obstructions. When performing daily checks, listen for unusual noises, vibrations, or changes in the machine’s performance, as these can be early indicators of wear or a developing fault. Maintain a log of daily observations, noting any abnormal findings and the actions taken to address them. This practice supports proactive maintenance and helps you trace issues back to their source if a problem arises later.
Periodic maintenance intervals and procedures require following a structured plan aligned with hours of operation or calendar time, as specified by the manufacturer. Typical intervals include inspections of the engine, transmission, hydraulic system, and cutting deck, along with replacement of consumables such as filters and fluids. At the designated intervals, perform a comprehensive inspection of the fuel system for leaks, inspect the exhaust system for signs of damage or overheating, and verify that all hoses and clamps are secure. Replace oil and hydraulic fluids according to the service interval recommendations, and renew the air filter, fuel filter, and lubricants as specified. A thorough periodic check also includes inspecting electrical connections, testing safety interlocks, and ensuring that the blade spindle and drive belts show acceptable wear with no signs of cracking or glazing. Maintain records of all performed maintenance, including part numbers, service dates, and measured readings to support warranty compliance and future service planning.
During periodic maintenance, calibrate and test the machine’s operational parameters to ensure performance matches factory specifications. This may involve checking engine idle speed, throttle response, hydraulic pressure, and transmission shifting behavior. If accessories or attachments are installed, inspect their mounting points and alignment to prevent undue stress on the chassis. Use only OEM-approved parts and lubricants, and follow the prescribed torque values when reassembling components. Proper preventive care reduces the likelihood of unexpected downtime, extends the life of critical components, and helps maintain the machine’s resale value. Always adhere to safety procedures, disconnect power sources, and wear protective equipment when performing maintenance in order to minimize risk to personnel involved in service work.
In addition to scheduled tune-ups, establish a routine for keeping the cutting deck clean and balanced. Remove debris after each use, inspect for bent or damaged components, and verify the condition of the blade(s) for sharpness and proper balance. A sharp, well-balanced blade improves cutting efficiency and reduces engine load, contributing to longer engine life and more consistent mowing results. Regular deck leveling and belt tension checks are essential to maintain uniform cutting height and prevent uneven wear on drive components. Document any adjustments made during deck maintenance and confirm that all guards and safety features remain properly in place after servicing. This ongoing attention to detail supports safe operation and predictable performance over the machine’s service life.
Engine System Overview and Service Procedures
The Exmark LAS28KA724 uses a robust engine designed for reliable performance in demanding outdoor conditions. Understanding the engine type and its major components is essential for accurate diagnostics and effective maintenance. Key components typically include the carbureted or EFI powerhead, intake manifold, exhaust system, oil sump, fuel delivery system, cooling passages, and electrical connections that support starting and sensing operations. A high-level familiarity with these parts helps technicians identify wear patterns, leaks, and potential failure points during routine service. Regular inspection of hoses, clamps, gaskets, and fasteners ensures the engine remains sealed, properly aligned, and capable of delivering consistent power output under load.
Fuel system inspection and service are critical to prevent stalling, loss of power, or hard starting. Begin with a visual check for fuel leaks around the tank, lines, and fittings, and confirm that the fuel quality is appropriate for the engine’s requirements. Inspect and replace fuel filters as needed, and ensure that all connections are secure and free from cracks or signs of deterioration. When diagnosing performance issues, test fuel pressure and flow to confirm that the fuel delivery system maintains proper pressure through the entire operating range. If ethanol-blended fuels are used, consider stabilizers and periodic drain and clean procedures to remove varnish and sediment from the carburetor or injectors.
Air intake and exhaust maintenance play a major role in ensuring efficient combustion and engine longevity. Inspect air filters for dirt, damage, and proper seating in the housing, replacing them according to the maintenance schedule or more frequently in dusty environments. Clean or replace intake ducts to prevent restricted airflow, which can cause detonation, power loss, or overheating. Examine the exhaust system for leaks, loose connections, and damaged gaskets, and ensure that the muffler and heat shields are intact and properly fastened. Excessive exhaust backpressure or leakage can lead to reduced performance and accelerated component wear, so address any issues promptly with the appropriate replacement parts or repairs.
Cooling system inspection and servicing are essential to maintain optimal operating temperatures and prevent overheating. Check all cooling fins, shrouds, and guards for cracks, blockages, or debris accumulation, removing obstructions with appropriate tools. Verify that the cooling fan is balanced and functioning, and inspect hoses or coolant passages for signs of wear or leakage if applicable to the engine model. Clean radiators or cooling fins using compressed air or a soft brush, taking care not to damage delicate fins. In air-cooled engines, ensure adequate airflow around the engine by keeping surrounding surfaces clear of grass clippings and debris that could impede ventilation.
Lubrication system servicing ensures proper lubrication of moving parts to minimize friction and wear. Confirm oil type, quantity, and viscosity as specified for the engine model, and perform regular oil level checks with the engine in a level position. Drain and replace oil at the recommended intervals, replacing the oil filter if the design requires it, and inspect for metallic contaminants that could indicate internal wear. Throughout lubrication procedures, verify that oil seals and gaskets are intact and that oil passages are free of obstructions. After servicing, run the engine for a short period to ensure oil pressure stabilizes and there are no leaks or abnormal noises indicating improper lubrication or misalignment.
The EXMARK LAS28KA724 service manual section on the fuel system begins with a practical overview of safe handling and preparation. Before performing any disassembly, ensure the engine is cool, the spark plug is disconnected, and the equipment is supported securely to prevent movement. Gather the correct replacement parts, including the fuel filter, any gaskets or seals specified for this model, and fresh fuel that meets the manufacturer's octane requirements. Label hoses and components as you remove them to aid accurate reassembly, and keep a clean workspace to prevent dirt or debris from entering the fuel system. This initial setup reduces the risk of contamination and helps maintain fuel system performance over the long term.
The fuel filter replacement procedure is described in a stepwise, methodical manner designed to minimize fuel spillage and air ingress. Start by locating the internal or external fuel filter within the fuel line, depending on the engine configuration of the LAS28KA724. Relieve any pressure in the fuel system according to the manufacturer's guidelines, then disconnect the lines using the appropriate wrenches without twisting the fittings. Remove the old filter, inspect the surrounding hoses for wear or cracks, and install the new filter with the correct orientation to ensure proper flow direction. After reassembly, prime the fuel system if required by the model, check for leaks at all connections, and dispose of the old filter in accordance with local regulations. Document the maintenance for future service intervals to support reliable starting and steady performance in the field.
The carburetor or fuel injection service steps emphasize precision and cleanliness to prevent contaminants from entering the system. When servicing a carbureted model, remove the air intake assembly to access the carburetor and carefully detach the throttle linkages and governor connections, noting their positions for accurate reassembly. Dismantle the carburetor components only as far as necessary to access the jet needles, idle screws, and passages, then clean with approved carburetor cleaners and lint-free cloths. Inspect the gaskets, seals, and float for signs of wear, and replace any compromised parts before reassembling. For fuel-injected variants, use diagnostic tools recommended by the manufacturer to verify injector pulse, fuel pressure, and sensor readings, and perform a thorough balance test after reassembly to ensure smooth engine operation. Refit all fasteners to specified torque values and perform a careful start-up sequence to confirm stable idle and no leaks, repeating the checks until the system remains consistent under varied throttle conditions.
The fuel line inspection and replacement section focuses on maintaining the integrity of all connections and routing. Inspect all fuel lines for cracks, hardness, swelling, or softened sections that can indicate aging and potential failure under pressure. When replacing lines, use OEM-spec hoses with the correct internal diameter and reinforcement to resist collapse and leakage, and ensure clamps are tight but not over-torqued to avoid damaging fittings. Verify that lines follow the original routing to prevent rubbing against moving parts or hot surfaces, which could shorten their life. After reinstalling lines, perform a pressure test or a controlled leak test as per the service manual, and monitor for any signs of seepage around clamps, fittings, and connection points. Document the inspection results and replace any fittings or elbows that show signs of wear, ensuring long-term reliability of the fuel delivery system in the Exmark LAS28KA724 model.
The Electrical and Wiring Harness Diagnostics section provides a practical, hands-on approach to identifying and resolving electrical faults in the Exmark LAS28KA724 mower. Begin by carefully reviewing the electrical schematics to understand the circuit pathways, connector pinouts, and color-coding conventions used throughout the machine. A methodical tracing of circuits from the power source through switches, relays, sensors, and actuators helps isolate fault regions without unnecessary disassembly. Always document observed voltages, continuity readings, and resistance values at each test point to build a reliable fault history that can guide corrective action. When in doubt, cross-reference component part numbers and harness identifiers with the service manual to ensure ratings and specifications align with the exact model configuration.
Accurate assessment of the battery, charging system, and alternator is critical to preventing frequent no-start conditions and intermittent electrical issues. Begin with a verified state-of-charge measurement using a calibrated multimeter, then inspect the battery terminals for corrosion and secure connections. Evaluate the charging system by monitoring the system voltage with the engine running at several RPMs to confirm the alternator maintains proper charging voltage within the specified range. Inspect the alternator belt condition and tension, and verify that the alternator output is properly distributed through the wiring harness to the power distribution module. Document any abnormal readings, such as voltage drops under load, which may indicate parasitic drains or internal alternator faults requiring replacement or overhaul of affected components.
Sensor and switch diagnostics focus on ensuring inputs to the engine control and safety systems are reliable. Start with a visual inspection of all sensors and switches for signs of wear, exposed wiring, or moisture ingress, particularly in high-vibration regions and near the operator console. Use a multimeter or oscilloscope to verify signal continuity and logical behavior across operational ranges; for example, ensure seat, PTO, clutch, and safety switches produce expected open/closed states when actuated. Replace any sensor with inconsistent readings or a persistent fault code, then recheck the related circuit for proper grounding and shielding to prevent future noise issues. When wiring harness faults are suspected, perform a controlled resistance test along harness segments to isolate high-resistance joints or damaged insulation, and follow color-coded tracer paths to identify compromised connectors that may benefit from cleaning, reseating, or replacement.
Throughout all diagnostics, maintain a clean, dry work environment and use appropriate PPE. Disconnect the battery before performing any invasive work on wiring to prevent short circuits or personal injury. When reassembling, ensure all fasteners are torqued to manufacturer specifications and that protective conduits and loom are correctly seated to avoid abrasion. After completing repairs, perform a functional test by operating the mower through its standard cycles and monitoring the electrical system for consistent performance, including startup reliability, accessory operation, and indicator light behavior. Finally, log all measurements, component replacements, and test outcomes in the service records to support future troubleshooting and warranty compliance.
The EXMARK LAS28KA724 starting and charging system requires careful diagnosis to ensure reliable operation. Common starting issues often stem from weak battery condition, loose or corroded connections, or damaged starter components. Begin by inspecting the battery for proper voltage, ensuring it is within its rated spec, and check electrolyte levels if applicable. Verify that all battery terminals are clean, tight, and free from corrosion, and inspect cable insulation for signs of wear or damage. If the engine turns slowly or fails to crank, test the battery under load to determine if it can sustain cranking amperage. Inadequate cranking performance can also be caused by excessive parasitic draw from electrical accessories or a Faulty ignition switch, so plan a systematic check of these circuits as part of the diagnostic process. When cranking remains inconsistent after a battery replacement or load test, inspect the starter solenoid and starter motor for signs of wear, sticking, or timing issues. Replacing or repairing defective starter components often resolves intermittent or no-crank conditions and restores reliable starting performance. Finally, confirm that the fuel system and safety interlocks are not inadvertently inhibiting starting, as these subsystems can mimic starting faults if misadjusted or malfunctioning.
Charging system troubleshooting begins with verifying proper alternator operation and ensuring charging voltage is within the manufacturer’s specified range. Start by disconnecting non-essential electrical loads to obtain an accurate reading of the charging voltage across the battery terminals with the engine running at a steady idle. If the voltage is significantly below or above the specified range, inspect the drive belt for tension and wear, and verify that it is aligned properly on all pulleys. A slipping or frayed belt can reduce alternator output, leading to insufficient charging of the battery during engine operation. If the belt and pulleys appear in good condition, test the alternator directly for output using the appropriate diagnostic procedure, ensuring safe access and adherence to service guidelines. In cases of poor charging, examine electrical connections at the alternator and battery for cleanliness and integrity; corroded or loose connections can impede current flow and mimic charging failure. Should the alternator prove faulty, replacement with a correctly rated unit is required to restore proper charging and prevent battery depletion during operation. Additionally, monitor for parasitic drains when the engine is off, which can continually deplete the battery and create misleading charging symptoms. By following these steps, technicians can accurately identify whether the issue lies with the alternator, wiring, or other components in the charging circuit and implement a durable repair.
The troubleshooting flowchart for starting and charging systems provides a structured path to isolate faults efficiently. Begin at the observed symptom: no crank, slow crank, or no charging. For a no-crank condition, verify battery voltage, inspect terminals, test the starter and solenoid, and confirm ignition switch operation before proceeding to component replacement. If cranking is slow but consistent, focus on battery health, cable integrity, and parasitic draw while verifying the starter performance. For a charging problem, measure the system voltage with the engine running and inspect the belt, connections, and alternator output. If readings indicate improper charging, systematically inspect related subsystems, including fuses, relays, and grounds, to locate the fault. In all cases, document the steps taken and the observed measurements to ensure repeatability and to aid in future service actions. The flowchart approach minimizes guesswork, helps technicians prioritize inspections, and supports efficient repair timelines while maintaining safety standards during diagnostic procedures.
Diagnostics and Troubleshooting Guide
When diagnosing a malfunction on the EXMARK LAS28KA724, begin with a calm, methodical approach that prioritizes safety and system understanding. Start by confirming the exact symptoms the operator reports and observe the machine in a controlled environment to reproduce the issue. Document any abnormal noises, warning indicators, or performance degradation, as these clues guide the fault isolation process. Gather all relevant service data, including recent maintenance history, software updates, and any recent changes to the machine configuration. This foundational step ensures that subsequent steps target the correct subsystem and reduces the risk of overlooking a secondary issue that could complicate repairs.
Accurate interpretation of error codes is essential for efficient troubleshooting. Many codes are stored in the controller memory and may be latched or current; verify whether the fault is active or historical. Cross-check displayed codes with the machine’s service manual to confirm the exact meaning and recommended corrective actions. If multiple codes appear, prioritize those related to drive system, fuel or ignition, and safety interlocks, as these areas most commonly generate operational faults. Remember to perform a visual inspection for electrical connectors, harness damage, corrosion, and obvious mechanical wear that could trigger sensor faults or intermittent errors. Document each code, its perceived symptom, and the condition under which it appeared to build a complete diagnostic profile.
Interpretation of error codes should be followed by step-by-step fault isolation procedures designed for clarity and safety. Begin with non-destructive checks that do not require disassembly, such as verifying battery voltage, fuse continuity, and connector integrity, then advance to sensor and actuator tests using appropriate diagnostic tools. For fuel and ignition systems, inspect fuel quality, line pressures, and spark parameters, ensuring that safety shutoffs and kill switches function correctly. In the hydraulic or drive subsystems, check pressures, leak points, and alignment with manufacturer specifications, using the approved test ports and gauges. Each test should have pass/fail criteria and documented corrective actions, so that technicians can systematically confirm root cause and prevent recurrence by addressing underlying causes, not just the symptom. Conclude by rechecking the original fault condition to ensure that the repair was effective and that no new faults have arisen during servicing.
When troubleshooting, maintain a detailed service log that captures the sequence of tests performed, measurements recorded, parts replaced, and any programming or calibration changes. For software-related faults, ensure that all firmware versions are up to date according to EXMARK’s recommended baselines, and perform a controlled test run in a safe environment to verify that all subsystems operate within specification. If a fault persists after following the prescribed steps, escalate to a higher level of diagnostics such as module reinitialization, diagnostic session capture, or component replacement with verified service parts. Always adhere to the manufacturer’s torque specifications, clearance limits, and safety procedures to protect both the technician and the equipment during extended diagnostic sessions.
Hydraulic fluid requirements and reservoir inspection are foundational for reliable operation of the EXMARK LAS28KA724. Use OEM-recommended hydraulic fluid that meets the viscosity and specification requirements listed in the service manual and operators' literature. When selecting fluid, verify the correct designation for the operating temperature range and avoid mixing brands or formulations unless explicitly approved. Regularly check the reservoir level when the engine is off and the system is cool to prevent overfilling, which can cause aeration and reduced performance. Inspect the reservoir for signs of contamination, such as water intrusion, rust, or particulate matter, and ensure the breather cap is clean and free of obstructions to prevent pressure build-up. Periodically sample hydraulic fluid to assess color, odor, and clarity; if the fluid appears milky, excessively dark, or smells burnt, perform a more thorough fluid change after addressing any leaks or overheating issues. Maintain proper container labeling and ensure all hydraulic caps, fill plugs, and sight gauges are securely seated to prevent air ingress and fluid loss during operation.
Drive belt and pulley inspection require careful attention to alignment, tension, and wear to ensure smooth traction and consistent PTO performance. Start with a visual inspection of all belts for cracks, fraying, glazing, or missing teeth, and replace any belt that shows signs of significant wear. Check belt tension according to manufacturer specifications, using a calibrated tension gauge or the method recommended in the service manual, and adjust as needed to avoid slip or excessive wear. Inspect pulleys for cracks, groove wear, excessive rust, or wobble when rotated by hand; replace damaged pulleys to prevent belt derailment. Ensure belt alignment is true by measuring pulley centers and verifying that grooves and belts are seated properly within the pulley rims. After replacing belts or pulleys, recheck tension and alignment and perform a brief test run to confirm there are no abnormal noises or vibration indicating misalignment. Finally, lubricate any serviceable bearings or idlers with the recommended lubricant type and avoid over-lubrication, which can attract dirt and reduce belt life.
Transmission and drive system service procedures encompass inspection, fluid management, and linkage adjustments to maintain optimal power transfer and operator control. Begin by assessing the transmission case for signs of leakage, cracks, or seepage around seals and gaskets; replace any compromised seals using OEM parts and torque to the specified values. Check transmission fluid level and quality, noting color, viscosity, and presence of particulates; drain and replace periodic fluids according to the maintenance schedule and service intervals. Inspect control linkages, cables, and mounting hardware for looseness, wear, or misalignment; adjust or replace components as necessary to ensure precise throttle and speed response. When performing service procedures on the drive system, ensure the machine is parked on a level surface and the ignition is off to prevent accidental movement; engage the parking brake and use wheel chocks for added safety. After completing service, perform a functional test under load to verify smooth engagement of drives, proper slowing and stopping, and absence of unusual noises, vibrations, or overheating that would indicate a need for further adjustments or component replacement.
The EXMARK LAS28KA724 mower requires careful attention to its cooling system to ensure peak performance and long engine life. Proper coolant specifications are essential, as using the incorrect coolant can lead to overheating, corrosion, or reduced heat transfer. Verify that the coolant meets the manufacturer’s recommended specification for the engine model installed in this unit, typically a high-quality ethylene glycols-based formula with appropriate rust inhibitors and distilled water. You'll want to prepare a fresh mixture according to the engine manufacturer's guidelines and the local climate, especially in regions with extreme temperatures. Record the replacement interval in the maintenance log, and schedule coolant changes at the intervals specified by EXMARK or by the engine manufacturer to prevent coolant degradation and the buildup of scale or particulate matter in the cooling passages.
Regular inspection of the cooling system begins with confirming the coolant level when the engine is cool to avoid pressure-related injuries. Check for signs of coolant leaks at hoses, clamps, the radiator, and the reservoir, noting any dampness, puddles, or white crust around the fittings. Inspect the radiator fins for debris, bent fins, or signs of corrosion that could impede airflow and reduce cooling efficiency. A clean radiator and unobstructed airflow are critical in hot weather or during heavy mowing tasks. If you notice a drop in cooling efficiency, perform a coolant quality test and replace the fluid if it appears contaminated or degraded beyond the recommended age or usage cycles.
Thermostat, hoses, and radiator integrity form the core of dependable cooling performance. The thermostat should open within the specified temperature range to regulate engine temperature and prevent overheating; if the engine runs hotter than normal or experiences temperature fluctuations, verify thermostat operation and replace it if it sticks or fails to open. Inspect all rubber hoses for signs of aging, such as elasticity loss, cracking, hardening, bulging, or soft spots, and replace damaged hoses promptly to prevent leaks or over-pressurization. Ensure hose clamps are secure and free of corrosion, and replace any clamps that show signs of rust or wear. When inspecting the radiator, look for leaks at the core, tanks, and seams, and ensure the radiator cap maintains the correct pressure rating. If the cooling system is not maintaining proper temperatures, perform a pressure test to identify hidden leaks and confirm the integrity of the radiator and related ports.
During routine maintenance, it is prudent to purge any trapped air from the cooling system after refilling. Air pockets can reduce coolant circulation and create localized overheating conditions, which may stress the engine. Follow the manufacturer’s procedure for venting air, which typically involves slowly warming the engine to operating temperature with the cap removed or loosened in a controlled manner, then topping off the coolant as air escapes. After venting, recheck the system for leaks and confirm that the coolant maintains the proper level with the engine cool. Document the date of the service, coolant type, and replacement or inspection results to facilitate future maintenance planning and to support warranty requirements.
In addition to routine checks, establish a visual inspection routine before each mowing session. Look for coolant residue on the ground, oozing around hose connections, or signs of moisture near the radiator. If you detect any abnormal odors or a sweet, syrupy smell near the engine compartment, treat it as a potential coolant leak and address it immediately to prevent engine damage. Maintaining proper coolant concentration, clean radiators, intact hoses, and secure clamps will help ensure reliable operation, reduce the risk of overheating during peak workload, and extend the service life of the cooling system components on the EXMARK LAS28KA724.
For more advanced troubleshooting, consult the engine manufacturer’s service bulletin on cooling system faults and use OEM replacement parts when available. If the radiator appears clogged beyond simple cleaning, or if persistent overheating occurs despite correct coolant levels and intact hoses, it may be necessary to perform a more thorough inspection of the water pump, thermostat housing, and heat exchanger connections. Always follow safety procedures when depressurizing the cooling system and wear appropriate protective equipment. Adhering to these guidelines will keep the cooling system performing at its best and help prevent costly downtime due to overheating on this EXMARK model.
The EXMARK LAS28KA724 service manual requires careful inspection of the frame, steering, and suspension to ensure safe operation and optimal performance. Begin with a thorough visual inspection of the chassis for any signs of structural damage, including cracks, bent members, or corrosion that could compromise rigidity. Pay particular attention to mounting points, welding seams, and the engine mounting area, as stress from operation can propagate hairline fractures over time. Use a calibrated straightedge or a level to verify that the frame rails are true and aligned, and check for any sag or misalignment that could affect steering geometry or ride quality. Document all findings with clear notes and photographs to support maintenance records and future inspections.
Steering linkage and alignment checks require meticulous measurement of both the input and output components to confirm proper travel, free play, and alignment. Start by inspecting tie rods, drag links, and pitman arms for wear, bend, or looseness, and replace any worn or damaged parts to maintain precise steering control. Measure toe-in and toe-out using a verified alignment method, ensuring that front tires point toward a common reference plane within manufacturer specifications. Check for steering column play at the steering wheel and inspect the steering shaft for any binding or abnormal noises during rotation. After adjustments, re-check all fasteners for torque accuracy and re-check alignment to ensure the steering system remains centered during operation.
Wheel and tire assessment encompasses platter contact, tread wear patterns, and mounting integrity to guarantee stable handling and traction. Inspect wheels for cracks, bent rims, or corrosion at lug nut seats and verify that all fasteners are torqued to the specified values in the service data. Evaluate tire condition, including tread depth, sidewall cracks, bulges, and uneven wear that could indicate prior misalignment or suspension issues. Rotate tires according to the OEM interval to promote even wear if applicable, and inspect wheel bearings for smooth rotation without perceptible play or grinding. Finally, examine the suspension mount points and linkage for looseness, worn bushings, or damaged bushings that could degrade ride quality or steering response, and replace components as needed to restore proper geometry and handling characteristics.
Safety, emission, and compliance are foundational concerns for any exterior power equipment, and the EXMARK LAS28KA724 is no exception. Before performing any maintenance or repair tasks, ensure all safety devices are intact and functioning, including blade brakes, kill switches, and parking brakes. Verify that the machine is on a stable, level surface with the ignition off and the spark plug wire removed or a dead battery isolated to prevent accidental starting. When inspecting safety interlocks, test each one in position to confirm it prevents engine start when any guard or lever is disengaged. Documentation of interlock performance should be recorded as part of the preventive maintenance routine to establish a verifiable safety baseline.
Interlocks are a critical part of operator protection and must be tested regularly according to the manufacturer’s schedule. For the LAS28KA724, confirm that the seat switch, PTO switch, blade engagement lever, and reversing safety mechanism do not allow the engine to start or the blades to engage if the operator is not in the seat or if guards are removed. If any interlock is susceptible to wear, misalignment, or interference from debris, address the root cause promptly. Do not bypass or defeat interlocks, as doing so can create dangerous operating conditions and void warranty coverage. When components are found defective, replace them with OEM parts and test the system comprehensively after installation to ensure proper function across all operating modes.
Emission control components are designed to minimize environmental impact while maintaining performance. The LAS28KA724 uses an exhaust management system that includes catalytic elements and a fuel metering strategy calibrated for efficiency and compliance. Service notes include inspecting the exhaust outlet for blockages, checking the integrity of the muffler and heat shields, and verifying that there are no exhaust leaks that could pose health risks or reduce engine efficiency. Periodic inspection should also cover the air intake system for obstructions, loose hoses, or damaged clamps that could affect fuel-air mixture and emission performance. Any replacement parts should meet or exceed OEM specifications to preserve both emissions compliance and engine reliability over the life of the machine.
In addition to component-level checks, maintain a clean operating environment to support safe emission performance. Ensure that the surrounding area is well-ventilated when testing or running the engine, and never perform maintenance under a hot exhaust or in confined spaces that could accumulate dangerous fumes. Proper torque on fasteners related to the exhaust and safety system is essential, so use a calibrated torque wrench and follow the service manual’s specifications. Record all inspections, replacements, and test results in the service log to provide a complete traceability record for compliance audits and future maintenance planning.
Finally, adhere to all applicable environmental regulations and local ordinances regarding emissions and disposal of used components. Safely collect and recycle or dispose of spent catalysts, filters, and/oil-impacted materials according to manufacturer guidelines and jurisdictional requirements. Maintaining an organized, documented approach to safety and emissions ensures the machine remains compliant, reliable, and safe for daily operation across diverse mowing environments and workloads.
General disassembly approach is the foundation of safe and efficient service work on the EXMARK LAS28KA724. Begin by reviewing the machine’s service indicators, serial numbers, and any manufacturer notes that pertain to this specific model. Before touching any fasteners, ensure the unit is powered down, the ignition key is removed, and the battery is disconnected to prevent accidental starts. As you remove covers and shields, photograph each step and label fasteners by location, as this practice reduces the risk of incorrect reassembly. Use the correct tools for each fastener size to avoid stripping, and keep a clean workspace with a tray or magnetic mat to hold small parts. When dealing with belts, pulleys, or tensioning systems, note the direction of movement and the alignment marks; these cues are essential for restoring proper tension and belt tracking during reassembly. Finally, establish a consistent sequence for disassembly that mirrors the recommended service procedure, ensuring you can retrace steps if an inspection reveals an upstream issue or a need for deeper access to components behind panels.
Component reassembly verification and testing requires meticulous attention to detail to ensure the mower operates safely and reliably after service. Begin by reinstalling major assemblies in the reverse order of disassembly, confirming that all fasteners are torqued to the manufacturer’s specifications and that any gaskets or seals are correctly seated to prevent leaks. Carefully reconnect electrical connectors, harnesses, and safety interlocks, ensuring that each connector is fully seated and locked to avoid intermittent faults. After mounting components, manually rotate moving parts such as blades or drive belts to verify smooth operation and absence of interference before applying power. Reconnect the battery, re-engage safety switches, and perform a cautious power-on test with the engine off to verify that all indicator lights function correctly and that no fault codes are present in the system’s diagnostic interface. Finally, conduct a controlled start and run test on a safe, open area, observing for abnormal vibrations, unusual noises, or misalignment, and address any issues immediately to prevent accelerated wear or safety hazards during regular operation.
Documentation and record keeping are essential practices for maintaining the reliability and safety of the EXMARK LAS28KA724 riding mower. Accurate maintenance logs help technicians track service intervals, monitor component wear, and plan proactive repairs before failures occur. Consistent record keeping also supports warranty claims and resale value by providing verifiable history of maintenance actions, parts replacements, and diagnostic steps. When documenting work, include the date, technician initials, mower serial number, hours of operation, and a concise summary of the performed actions. This disciplined approach reduces downtime and improves overall machine availability for demanding mowing schedules.
Maintenance log templates should be clear, standardized, and easy to fill out in the field. A typical template includes sections for routine inspections, lubrication points, filter changes, belt tension checks, blade sharpening, and safety system verifications. For each entry, record parts used, part numbers, cost, and the technician’s notes on condition or anomalies observed. It is helpful to attach or reference service bulletins, diagnostic codes, and any adjustments made to the cutting deck or drive system. Keeping a digital copy of the template, alongside a printed, sign-off sheet, ensures redundancy and protects against data loss in harsh outdoor environments.
Parts replacement and service history must be meticulously documented to ensure traceability and future maintenance planning. Each replacement should note the exact part number, supplier, lot/date codes, and a brief justification for the replacement. Include the odometer-like hours meter reading if applicable, the type of lubrication, torque specifications, and any safety tests performed after installation. When feasible, capture before-and-after photos of critical components such as the deck spindles, drive belts, and hydraulic fittings to provide a visual reference for wear patterns over time. A well-maintained service history enables efficient diagnostics, reduces the risk of recurring issues, and supports warranty adjudication when needed.
In addition to the standard entries, implement a routine for periodic audit and reconciliation of maintenance records. Cross-check part usage with inventory to prevent discrepancies and ensure that stocking levels align with service demands. Establish a review cadence where senior technicians verify entries for accuracy and completeness, signing off on the documentation. This practice not only enforces accountability but also promotes knowledge transfer within the maintenance team, helping new technicians learn proper record-keeping conventions quickly.
For the EXMARK LAS28KA724 specifically, maintain a dedicated service history file that includes model-specific maintenance recommendations from the manufacturer, such as recommended filter replacement intervals, lubrication points, and belt tensioning procedures. Ensure any updates to service procedures or parts alerts are incorporated into the records promptly. By adhering to thorough documentation and record keeping, operators can maximize uptime, extend equipment life, and maintain safe, high-performance operation of their mowing system.