WRIGHT WS52FX691E Service Manual
Overview
The Wright WS52FX691E represents a compact, yet capable outdoor power equipment platform designed for reliable performance in a variety of residential and light commercial settings. This section outlines the fundamental purpose of the unit, its core capabilities, and the boundaries within which maintenance and repair should be performed. Understanding these elements helps technicians approach service tasks with an accurate expectation of the machine’s intended function and operating environment. Proper adherence to the documented scope reduces the risk of unintended modifications that could affect safety or performance.
The primary purpose of the WS52FX691E is to provide efficient cutting, mulching, or hauling operations depending on the configured attachments and deck specifications. The design emphasizes durability, operator comfort, and ease of routine maintenance, which are essential for maximizing uptime in field conditions. It is important to recognize the machine’s limitations in terms of operating temperature range, load capacity, and permissible use scenarios to avoid overstressing components. Technicians should familiarize themselves with the serviceable modules, including the drive system, cutting deck, hydrostat or transmission unit, and electrical harness, to plan effective diagnostic strategies when issues arise.
Intended audience for this service manual section includes qualified technicians, dealership service personnel, and knowledgeable do-it-yourself enthusiasts with a strong emphasis on safety and proper technique. The material is written to support accurate troubleshooting, preventive maintenance, and methodical repair procedures. It assumes a baseline familiarity with common power equipment terminology, torque specifications, and factory procedures. Readers should follow all safety warnings and use appropriate personal protective equipment during disassembly, adjustment, and testing to mitigate the risk of injury or equipment damage.
In addition to routine maintenance, this overview highlights the importance of verifying compatibility between replacement parts and the WS52FX691E’s specific service model. Variations in serial number ranges or production batches may introduce subtle differences that influence recommended service intervals or component fitment. Technicians should cross-reference the machine’s data plate and service literature before ordering parts or initiating any repair to ensure proper alignment with the correct warranty and performance criteria. A clear understanding of these factors supports accurate diagnosis and efficient restoration of peak operating condition.
Finally, the overview underscores the role of proactive inspection as a cornerstone of reliable operation. Regular checks on critical systems such as fuel delivery, air filtration, lubrication, electrical connections, and drive components help preempt failures that could lead to downtime or unsafe operating conditions. The manual encourages documenting observed conditions, service actions taken, and parts replaced to build a traceable maintenance history. This practice not only supports future troubleshooting but also enhances the overall life cycle management of the Wright WS52FX691E.
Safety and compliance
Personal protective equipment is essential when performing maintenance or repair on the WRIGHT WS52FX691E. Always use eye protection such as safety goggles or face shields to guard against debris, dust, and fluid splashes. Wear cut-resistant gloves to protect hands during handlebar, cable, and blade work, and use hearing protection when operating or testing powered components. A sturdy, non-slip pair of work boots and long sleeves can help prevent minor injuries from moving parts or heated surfaces. Ensure all PPE is in good condition, properly fitted, and readily accessible before beginning any service procedure.
Hazard notifications are critical to maintaining a safe work environment. Before starting any repair, disconnect the power source and remove the battery if applicable to prevent accidental starting or electric shock. Keep all bystanders away from the work area and establish a clear perimeter to avoid trip hazards from tools, cords, and parts. Be aware of hot engine surfaces, sharp blades, and moving drive components that can cause severe injuries. Post visible hazard alerts and ensure proper lockout/tagout procedures are followed if the machine is integrated into a larger fleet or facility maintenance routine.
Environmental considerations play a significant role in both safety and compliance. Dispose of used oil, fuel, filters, and batteries according to local environmental regulations and manufacturer recommendations, never dumping fluids on the ground. Minimize fuel spillage by using approved containers, maintaining clean work surfaces, and promptly addressing any leaks. When testing the equipment, operate in a well-ventilated area to reduce exposure to exhaust and fumes, and implement appropriate containment for potential coolant or solvent leaks. Additionally, ensure that the machine is stored in a dry, secure location to prevent corrosion and tampering, and follow all applicable environmental laws for waste management and emissions control.
Technical specifications
The Wright WS52FX691E is a compact commercial-grade outdoor power equipment machine designed for reliable daily operation in demanding work environments. Correct identification of the model and its serial data is essential for service, parts replacement, and maintenance scheduling. The identifier information typically includes the model number, serial number, production date, and firmware or controller revision if applicable. Recording these details at the start of every service interval helps ensure the correct service procedures and compatible components are used, reducing downtime and preserving machine performance. Always verify that the unit on hand matches the documented specification to prevent mismatched parts or incorrect service steps.
Power requirements and electrical system details define how the machine is powered and how electrical safety is ensured during operation. The WS52FX691E generally relies on a robust power supply suitable for commercial use, with considerations for starter circuits, battery or alternator charging systems, and any auxiliary power ports used for peripheral equipment. Electrical connections should be inspected for secure terminals, proper gauge wiring, and absence of insulation damage. Safety interlocks, dead-man switches, and protective covers must be present and functioning to prevent unintended operation while maintenance is performed. When diagnosing electrical faults, reference the color codes, connector housings, and harness routing to locate and repair issues efficiently without compromising system integrity.
Lubrication and fluids specifications cover the recommended types, capacities, and maintenance intervals for all moving parts and fluid systems on the machine. This includes engine oil, hydraulic fluid, transmission lubricant, fuel specifications, and any specialty lubricants required for control linkages or drive assemblies. Use the specified viscosity and grade as outlined by the manufacturer to maintain optimal performance and extend component life. Regular checks should include fluid levels, color, contaminants, and seal condition, with prompt replacement when signs of wear or contamination appear. Accurate lubrication schedules help prevent excessive wear, reduce fuel and oil consumption, and ensure smooth operation of steering, propulsion, and hydraulic functions during routine use. Always adhere to the recommended intervals and quantities when performing servicing to avoid under- or over-lubrication that could affect machine reliability.
Maintenance fundamentals
Preventive maintenance for outdoor power equipment like the Wright WS52FX691E involves establishing a regular, detail-oriented routine that extends the life of the machine and ensures safe, reliable operation. Begin with a clear maintenance calendar that aligns with manufacturer recommendations and your usage patterns. Document every service interval, what was inspected, what was replaced, and any observations or anomalies found during the process. This proactive approach helps catch wear before it leads to component failure and costly downtime. It also enhances operator safety by maintaining critical systems in optimal condition. Regular maintenance should be performed by trained personnel or individuals with a solid understanding of mechanical, electrical, and hydraulic basics as applicable to this model.
Establish a preventive maintenance schedule that covers daily, weekly, monthly, and seasonal tasks. Daily checks should focus on fuel, oil levels, coolant, battery condition, and visible leaks or loose fasteners. Weekly routines can include air filter inspection, belt tension and wear checks, lubrication of pivot points, and a quick diagnostic of electrical systems. Monthly duties expand to a more thorough inspection of safety systems, spark plugs or ignition components, fuel lines, hose fittings, and the condition of cutting blades or attachments. Seasonal maintenance may entail more comprehensive engine service, cooling system flushes if applicable, and alternator or charging system verification. A well-structured schedule minimizes downtime and preserves machine performance across changing operating conditions.
Inspection procedures should be methodical and repeatable. Start with a clean surface to ensure you can see contaminants and wear clearly. Visually inspect all critical assemblies for cracks, corrosion, and deformation. Listen for unusual noises during operation and perform a functional test to confirm proper engagement of safety interlocks, drive systems, and braking mechanisms. Use manufacturer-recommended torque values and inspection criteria for fasteners and connections, and replace any parts that show signs of excessive wear or damage. Document inspection results with notes and photographs when helpful, and compare current findings to previous records to identify progressive wear. A systematic approach to inspections reduces the risk of hidden failures that could result in sudden downtime or safety incidents.
Replacement part guidelines emphasize using genuine or recommended components that meet or exceed the original specifications. Maintain an organized inventory of spare parts, including filters, gaskets, seals, belts, and consumables, and replace them according to the prescribed service intervals or as condition dictates. Prioritize items with a known wear pattern on the Wright WS52FX691E, such as lubrication points, blade or cutter components, and drive system elements. When selecting replacements, verify compatibility with your serial number and production year to ensure correct fit and performance. Dispose of e-waste and used parts in accordance with local regulations, and document part numbers, lot numbers, and installation dates for traceability. Consistent use of approved parts reduces the likelihood of premature failure and helps maintain resale value and reliability.
In addition to the core maintenance tasks, establish a routine for cleanliness and environmental care. Keep the equipment housing and cooling fins free of debris to maintain optimal operating temperatures. Use approved lubricants and anti-corrosion treatments where recommended, and ensure that all safety guards and shields are reinstalled after service. Periodically recalibrate gauges and indicators to reflect true operating conditions, and verify fluid levels after any maintenance work. A disciplined approach to maintenance not only preserves performance but also reinforces operator safety and confidence in the equipment during demanding tasks.
Safety precautions before disassembly: Before beginning any disassembly work on the Wright WS52FX691E, ensure the unit is parked on a flat, level surface and that the ignition key is removed to prevent accidental starting. Disconnect the battery or disconnect power sources as applicable to your model configuration, and depressurize any fuel lines if fuel system work is anticipated. Wear appropriate PPE, including cut-resistant gloves, safety glasses, and sturdy footwear, and keep a clean, organized work area with clearly labeled containers for fasteners. Document all steps with photos or notes to aid reassembly, and verify that all tools are in good condition and sized correctly for the fasteners encountered. Finally, consult the manufacturer’s warnings and local regulations regarding fuel, electrical safety, and machine handling to minimize risk during disassembly.
Removing external housings and guards: Begin by removing any protective guards and external housings that cover the underside, sides, and top of the chassis. Use the correct screwdriver or socket as specified by the fastener type, and keep all screws and clips organized to prevent misplacement. Gently pry panels away from mounting points to avoid bending or damaging the surrounding sheet metal, and disconnect any interlock switches or safety connectors that interface with the housing if present. When removing the shrouds surrounding the engine and drive components, note the routing of cables and hoses to prevent kinks or improper reassembly. After the housings are removed, perform a visual check of mounting brackets for cracks or deformation that could indicate prior stress and address any issues before proceeding. Ensure that all removed components are placed in a labeled container to simplify the reassembly process.
Accessing the engine and drive system: With housings removed, carefully expose the engine, cooling system, and drive components, taking care not to damage any belts, pulleys, or wiring harnesses. Inspect belt tensioners and drive belts for wear or oil contamination, and replace any suspect components in accordance with torque specifications and replacement intervals. Disconnect electrical connectors and fuel lines only after noting their orientation and securing any clamps to prevent accidental release during removal. When lifting the engine or drivetrain components for access, use appropriate lifting tools and support stands to maintain stability and avoid personal injury. After gaining access, perform a thorough inspection of cooling fins, air inlets, and the exhaust path for obstructions, and check for loose mounts or misaligned components that could affect performance. Reassemble by reversing the steps, ensuring all fasteners are torqued to spec, electrical connectors are engaged fully, and safety interlocks are reinstalled correctly to restore proper operation and safety compliance.
Engine system service
The engine system is the heart of the Wright WS52FX691E and requires careful inspection, cleaning, and routine maintenance to ensure reliable performance. Begin with a thorough visual assessment of the engine bay, checking for cracked hoses, loose connections, oil leaks, and signs of corrosion on metal components. Document any abnormal wear or damage and address it before proceeding with routine service. Verify that all protective shrouds and guards are securely in place to prevent debris intrusion and maintain safe operating conditions. Regularly inspect air intake pathways for obstructions such as leaves, dust, or grass clippings, which can restrict airflow and degrade engine efficiency. A clean, well-maintained engine compartment facilitates accurate diagnostics and longer component life.
Engine safety and performance hinge on using the correct fuel and oil specifications. Confirm that the fuel is fresh and stored in an approved container, and that the fuel is appropriate for the engine model with no contamination from water or particulates. When servicing the lubrication system, use the manufacturer-specified oil grade and capacity, and replace the oil with the recommended interval frequency. Always dispose of used oil and filters at an authorized recycling facility. Tighten oil drain and fill plugs to the specified torque and inspect the crankcase for leaks after completing oil changes. Following these steps helps prevent engine wear and ensures smooth, reliable startup and operation.
Fuel system service encompasses inspecting the fuel lines, filters, and pump for signs of wear, cracking, or leakage. Replace fuel filters according to the service interval and inspect the fuel tank for rust or sediment that could contaminate the carburetor or fuel injectors. When removing components for inspection, avoid bending fuel lines sharply and use appropriate protective caps to prevent dirt ingress. After reassembly, perform a priming procedure as specified by the manufacturer and verify that there are no air leaks in the fuel system. Proper fuel system maintenance reduces starting difficulties, improves engine performance, and extends the life of injectors and carburetion components.
Lubrication system maintenance focuses on ensuring that all moving parts receive adequate lubrication to minimize friction and heat buildup. Check the lubrication points, including bearings, gears, and linkages, and replenish lubricant to the recommended levels. Look for signs of contamination, such as metallic flakes or viscous, dirty oil, and address these issues promptly with a complete oil change and filter replacement if applicable. Pay particular attention to the cooling jacket and seals around the crankshaft to prevent oil leaks that could contaminate the drive belt or exhaust area. Regular lubrication reduces wear, lowers noise, and enhances overall engine efficiency and longevity.
Cooling system maintenance is essential to prevent overheating during prolonged use or high-load applications. Inspect the cooling fins, radiator (if applicable), hoses, and thermostat for blockages, cracks, or deterioration. Ensure coolant level is at the proper mark and replace coolant according to the service interval using the recommended mixture and specifications. Check the water pump, hoses, and clamps for leaks and secure connections, replacing any worn components. A properly maintained cooling system maintains optimal engine temperature, prevents performance drop-offs, and protects engine components from thermal damage.
Following a structured inspection and maintenance routine for the engine system helps sustain peak performance, reduce downtime, and extend the service life of the Wright WS52FX691E unit. Always use genuine parts when replacements are needed and consult the manufacturer’s torque specifications during assembly. Document all service actions with dates and part numbers to support warranty compliance and future maintenance planning. Establishing a regular preventive maintenance schedule is the best defense against unexpected failures and costly repairs, ensuring your equipment remains ready for operation when needed.
Drive and transmission systems are critical to the performance and longevity of the WRIGHT WS52FX691E. Regular inspection and proper maintenance of belts, clutches, and the transmission assembly help prevent unexpected downtime and costly repairs. Begin with a clean, well-lit workspace and ensure the machine is on a level surface with the ignition off and the battery disconnected before performing any procedures. Use manufacturer-approved replacement parts and reference torque specifications when reinstalling fasteners to maintain proper alignment and tension. Wear appropriate PPE, including eye protection and gloves, to protect against moving parts and sharp edges.
Drive belt inspection and adjustment
Inspect the drive belt for signs of wear, cracks, fraying, glazing, or chunking along the belt surface and at the pulley contact points. Check belt alignment in the pulley system by ensuring the belt sits squarely in the pulley grooves and tracks true during rotation without wobbling. Measure the belt’s width and compare it to the manufacturer’s specified service limits; any reduction beyond the recommended tolerance indicates replacement is necessary. When adjusting belt tension, use the prescribed method to avoid over-tightening, which can accelerate bearing wear and reduce belt life, or under-tightening, which can cause slippage and loss of drive efficiency. After making adjustments, rotate the engine or drive system by hand to verify smooth operation and absence of abnormal noise, vibration, or heat buildup during initial run-up.
Clutch and belt replacement procedures
Access to the clutch and belt assembly requires removing protective covers and, if applicable, engine shrouds. Prior to disassembly, note the orientation and routing of all belts and clamps to ensure correct reassembly. Remove the belt carefully from pulleys to avoid damaging grooves or adjacent components, and inspect the clutch for wear on the friction surfaces and spring tension. When installing a new belt, route it according to the original path and verify that all tensioning pulleys are correctly seated and free of debris. After replacement, perform a static check by manually rotating the drive and ensuring there is no binding or misalignment. Finally, start the engine at a low idle and gradually increase speed to confirm proper clutch engagement, smooth disengagement, and consistent belt tracking without slipping or excessive noise.
Transmission maintenance and service
Regular transmission maintenance begins with a thorough inspection of the transmission case for signs of leaks, cracks, or seepage from seals and gaskets. Check transmission fluid level and condition as specified by the manufacturer, looking for appropriate color, appearance, and absence of metallic debris or contamination. If drainage or refilling is required, perform the procedure with the proper type of fluid and the exact quantity recommended for the WS52FX691E model, ensuring the system is level during filling to achieve the correct specification. Rotate the drive system manually to distribute any new lubricant evenly through bearings and gears, and listen for unusual sounds that could indicate worn gear teeth or bearing damage. Schedule periodic checks of transmission mounts and linkage to maintain proper alignment and responsiveness, adjusting or replacing worn components as needed to preserve smooth operation and accurate gear engagement.
Electrical system and controls
The electrical system of the WRIGHT WS52FX691E is designed for reliable operation in a demanding outdoor environment. A robust wiring harness bundles power and control circuits to minimize interference and physical wear, while weather-resistant connectors protect critical connections from moisture and debris. When inspecting the system, check for signs of abrasion, loose terminals, or cracked insulation, especially at common flex points near the engine, switch panel, and battery tray. A clean, organized loom not only reduces the risk of shorts but also makes troubleshooting faster by preserving clear routing paths and identifying damaged sections quickly. Always use the manufacturer-specified harness routing as a reference to maintain electrical integrity during servicing or reassembly after maintenance work.
Wiring diagram overview: The schematic presents the relationships between the battery, alternator or charging source, control module, switches, and actuators. It highlights power supply lines, ground references, signal circuits, and fault indicators. Understanding the diagram aids in diagnosing no-start conditions, intermittent loss of function, or incorrect voltage readings. When interpreting the diagram, verify that the color codes on the harness match the service data and ensure that any modifications preserve the original current ratings and protection devices. Document any deviations from the standard routing to avoid confusion during future service procedures.
Battery and charging system service: The WS52FX691E relies on a robust 12V or equivalent battery setup to provide stable cranking power and to support electronic controls. Inspect battery terminals for corrosion, ensure conduit seals are intact, and confirm proper electrolyte levels if applicable. Test charging output with a multimeter while the engine is running to ensure the system maintains a steady voltage within the specified range; fluctuations can indicate a failing alternator, loose belt tension, or electrical leakage. Replace any battery that shows excessive internal resistance or a terminal that cannot securely clamp, and re-torque all fasteners per the manufacturer’s specifications after service. Regularly inspect battery cables for wear and replace damaged sections to prevent unexpected power loss during operation.
Control module diagnostics and testing: The control module governs key functions such as ignition, safety interlocks, PTO engagement, and accessory circuits. Diagnostic procedures typically begin with self-test codes or fault indicators, followed by targeted electrical measurements at the module connectors. Use an appropriate scan tool or manual-tested continuity checks to verify input signals from switches, sensors, and safety devices, and confirm correct output to actuators. When a fault is detected, isolate the affected circuit, inspect for shorts to ground, open circuits, or incorrect wiring, and correct any discrepancies before clearing faults. After repairs, perform a functional test that reproduces real operating conditions to confirm that the control system responds correctly to user inputs and safety conditions, ensuring reliable performance and operator safety.
Charging and safety systems
Charging and safety systems are integral to the reliable operation and long-term durability of the WRIGHT WS52FX691E. The charging system is designed to maintain optimal battery health while protecting the operator and equipment from potential electrical hazards. Proper understanding of interlocks, shutdown procedures, and battery handling ensures that maintenance tasks are performed safely and efficiently. Regular inspection of charging components, including connectors, cables, and fuses, helps prevent unexpected failures that could compromise performance or safety.
Safety interlocks and shutdown procedures are the first line of defense against accidental operation and exposure to hazardous conditions. Ensure all access panels are secured before starting any maintenance work, and verify that the seat switch, interlock sensors, and blade engagement mechanisms respond correctly when tested. In the event of an abnormal interlock reading or a non-responsive shutdown sequence, disconnect the power source, isolate the battery circuit, and consult the service manual for recommended diagnostic steps. Document any interlock faults and address them promptly to prevent unintended operation or injury during normal use.
Battery handling and safety measures require strict adherence to manufacturer guidelines and standard electrical safety practices. When charging or replacing batteries, use the specified charger, maintain proper ventilation to avoid the buildup of flammable gases, and wear appropriate personal protective equipment such as eye protection and gloves. Inspect battery cases for cracks or signs of swelling, loose terminals, and corrosion, replacing damaged components as needed. During handling, avoid short circuits and keep metal tools away from battery terminals to minimize the risk of sparks or thermal events that could lead to injury or equipment damage.
Emergency procedures and troubleshooting steps are essential for quick and effective responses to electrical faults or safety incidents. Establish clear alarm recognition for battery temperature rise, charger fault indicators, or abnormal voltage readings, and follow a predefined sequence to shut down power safely. In case of an electrical fire, use a Class B or appropriate fire extinguisher and evacuate the area as necessary before contacting emergency services. For troubleshooting, start with a visual inspection, followed by verifying cable continuity, connector integrity, and charger functionality using the manufacturer-approved diagnostic procedures. Maintain a detailed log of all findings, actions taken, and parts replaced to support ongoing maintenance and future fault isolation.
The cooling system of the Wright WS52FX691E is essential for maintaining optimal engine temperature and preventing overheating during extended operation. Regular inspection and careful maintenance of the radiator, cooling fins, and associated components help ensure consistent performance and longevity of the power equipment. Begin by visually inspecting the radiator area for debris, dust, and any bent fins that could impede airflow. Use a soft brush or compressed air at low pressure to remove accumulated material, taking care not to damage the delicate cooling fins. If fins are badly bent, carefully straighten them with a fin comb to restore proper airflow and heat dissipation. Ensure surrounding components do not obstruct airflow, and verify that the radiator cap remains in good condition to maintain proper pressure within the cooling system.
The thermostat and water pump are critical for regulating engine temperature and circulating coolant throughout the system. When inspecting, check for signs of leakage around seals and gaskets, and listen for unusual noises that may indicate a failing impeller or bearing. Remove the thermostat housing only after cooling down and inspect the thermostat for sticking or signs of corrosion; replace if necessary with the recommended part to restore proper temperature regulation. The water pump should exhibit smooth operation without wobble or excessive play in the shaft. Inspect the impeller for damage or excessive wear and verify that the pump seals are intact to prevent coolant loss. Reassemble with proper torque on mounting bolts and ensure the serpentine belt or drive belt tension is within specification to maintain consistent coolant circulation.
Guidelines for coolant replacement emphasize using the manufacturer-recommended coolant type and mixing ratio. Before draining, ensure the engine is cool to avoid scalding risks and to prevent coolant loss from pressure buildup. Drain the old coolant completely into an approved container and flush the cooling system with water to remove residue. Refill with the specified coolant mix to the correct level, then run the engine to circulate and bleed any air from the system. Check for leaks around hose connections, clamps, and the radiator cap after the system reaches operating temperature and the thermostat opens. Dispose of old coolant according to local environmental regulations and reset any maintenance reminder indicators if equipped.
Fuel system details
The fuel system in the WRIGHT WS52FX691E is designed to deliver a precise and consistent fuel supply to the engine under a variety of operating conditions. Begin by inspecting all accessible fuel lines for signs of wear, cracking, or softening, especially near connection points and where routing may cause flexing. Deteriorated lines should be replaced with OEM or equivalent high-quality lines that resist fuel permeation and heat. When inspecting, gently bend lines to reveal any hidden cracks, and use a fresh bottle of fuel to test for leaks at every joint. Keep the fuel system clean during inspection to prevent contamination that can lead to poor engine performance or starting difficulties. Regular inspection helps prevent fuel leaks, which can be hazardous and costly over time.
Injector and carburetor service requires careful attention to both air and fuel delivery paths. The injector or carburetor must atomize fuel correctly to maintain optimal combustion. Remove the injector or carburetor assembly and inspect the nozzle for clogging, varnish buildup, or damaged seals. Use a certified cleaner compatible with the fuel type for cleaning, and never force debris through passages, which can cause additional damage. After cleaning, verify proper spray pattern or idle mixture by performing a bench test if the service manual allows, ensuring the unit delivers a consistent and even discharge. Reassemble with new gaskets and torque fasteners to specification to prevent leaks and ensure reliable starting and performance. A correctly serviced injector or carburetor contributes to efficient fuel usage and reduced emissions in operation.
Fuel filter replacement is a routine maintenance task that protects the engine from particulates and contaminants that can cause scoring and poor fuel metering. Locate the fuel filter in the line between the tank and the carburetor or injector, depending on the exact configuration of the WS52FX691E. When replacing, relieve any built-up pressure safely and replace the filter with the correct rating and flow characteristics for the model. Inspect the filter housing for any cracks or wear, and ensure seals and O-rings are in good condition or replaced to maintain a proper seal. After installation, prime the fuel system as required by the manual to remove any air pockets and confirm that there are no leaks at connections. Regular filter changes improve engine longevity, maintain consistent power delivery, and help prevent lean or rich running conditions that could damage the engine over time.