2004–2005 Polaris Scrambler 500 Factory Service Manual (P/N 9919481)

• Coverage and document identity: Covers 2004 and 2005 Polaris Scrambler 500 4x4 ATVs - model A04BG50AA and models A05BG50AA/FA - with the EH500PLE liquid-cooled SOHC four-stroke engine. This is a 303-page PDF of Polaris Service Manual P/N 9919481.
• Engine and cooling repair: Documents engine removal and installation, top- and bottom-end disassembly, cylinder honing, valve-seat and cylinder-head service, crankshaft and counterbalancer inspection, cam timing, oil-pump service and priming, oil-pressure testing, water-pump work, cooling-system pressure testing, and bleeding.
• Fuel, PVT, and transmission systems: Details Mikuni BST 40 CV carburetor overhaul, jetting and fuel-level checks, needle-and-seat leakage testing, and fuel-pump service. The non-EBS PVT section handles drive and driven clutch repair, belt inspection, alignment and offset, bushing replacement, and overheating diagnosis; the H/N/Rev transmission section covers removal, teardown, reassembly, and troubleshooting.
• AWD, final drive, and suspension: Includes front hub and Hilliard clutch service, magnetic-coil testing, CV axle and boot repair, prop-shaft U-joints, front-housing overhaul, and separate 2004 and 2005 concentric-swingarm rear-axle procedures. Chassis coverage extends to A-arms, struts, ball joints, steering post, and swingarm service.
• Year-specific brakes and electrical diagnosis: Provides separate 2004 and 2005 hydraulic brake sections with bleeding, master-cylinder, pad, disc, caliper, and auxiliary-brake procedures. Electrical coverage includes ECM and thermistor tests, fan and hot-light operation, ETC, DC/CDI ignition, gear-position and reverse-limiter diagnosis, no-AWD fault charts, charging, battery, lighting, starter motor, and starter drive service.
• Factory data and technical illustrations: Supplies normal and severe-use maintenance schedules, component torque tables, fluid and lubrication data, wear limits, end-play and clearance specifications, jetting and clutch charts, electrical test values, specialized tool identification, exploded views, diagnostic flowcharts, and year-specific wiring diagrams.

Shop-Level Scope and Maintenance

Polaris wrote this manual primarily for certified Polaris Master Service Dealer technicians working in a properly equipped shop. It assumes a sound knowledge of mechanical theory, tool use, and shop procedures, making it shop-level material rather than a basic owner's maintenance guide. The opening chapter shows the machine, engine, and transmission identification locations and lists the separate owner and parts publications needed when ordering model-specific service parts.

Maintenance coverage goes well beyond routine oil changes. The periodic chart defines severe use and identifies the items that require shortened service intervals. Factory procedures address H/N/Rev shift-linkage adjustment, throttle and choke setup, ETC switch checks, carburetor adjustment, compression and ignition-timing tests, coolant inspection, valve-clearance adjustment, steering and toe alignment, AWD hub maintenance, drive-chain and sprocket service, suspension checks, and PVT drying after water entry.

Model-Year Repair Differences

The final-drive chapter separates 2004 and 2005 rear-axle removal, assembly, housing service, and exploded-view information instead of presenting one generic procedure. The brake chapter is also divided by model year, documenting each hydraulic layout and the separately serviced rear-caliper circuits, along with fluid replacement, brake burnishing, disc inspection, caliper overhaul, and system troubleshooting.

Engine coverage reaches full internal repair depth. In addition to top-end work, the manual addresses crankcase separation, main-bearing replacement, crankshaft, counterbalancer, and oil-pump shaft end-play checks, crankcase assembly, recoil service, and post-assembly cooling-system bleeding. Carburetion and electrical chapters add system-operation explanations before the related inspection and fault-isolation material, which helps distinguish an adjustment problem from a component failure.

Tools, Diagrams, and Specifications

Special-tool listings pair tool names with Polaris part numbers, including the Water Pump Seal Puller P/N 2872105, ATV Clutch Align Tool P/N 2870654, Shaft Drive Transmission & Front Gearcase Tool Kit P/N 2871702, and Mity Vac P/N 2870975. Reference material includes standard fastener torque charts, metric and SAE tap-drill tables, decimal equivalents, unit conversions, component-specific torque values, approved fluids and capacities, and inspection limits for the covered assemblies.

Named figures include the EH50PL Oil Flow Diagram, EH50PL Engine Exploded Views, BST 40 Carburetor Exploded View, AWD Front Hub Exploded View, 4x4 Transmission Exploded View, and separate 2004 and 2005 Scrambler 500 4x4 wiring diagrams.

Forcing Demand Drive Hub Fluid into the AWD hub under pressure can damage its seals, while operating with the Hilliard armature plate out of position can damage the roller clutch. The engine section also warns that incorrect cam-to-crank timing can cause serious internal damage. Follow the factory safety warnings and specified tool requirements for pressurized cooling-system work, hydraulic brake service, and spring-loaded PVT clutch repair.