Positioning:
The Polaris Sportsman 400 HO was positioned as a mid-range, versatile utility ATV, known for its comfort, capability, and value in the recreational and light work segments.
Competitors:
Competed with models from Yamaha (Grizzly 350/450), Honda (FourTrax Foreman 400/420), Can-Am (Outlander 400), and Kawasaki (Brute Force 300/400) during its production years.
Features:
Independent Rear Suspension (IRS), Polaris Variable Transmission (PVT), On-Demand True All-Wheel Drive (AWD), electronic fuel injection (on some later models, though 400 HO typically carbureted), comfortable seating, and robust cargo racks.
Coverage Scope:
Complete workshop service and repair
Specific Systems:
Engine, transmission, chassis, electrical, body, suspension, brakes, steering, fuel system, cooling system, exhaust system, drive train, differential, axles, wheels, tires, and more.
Estimated Page Count:
Likely 500+ pages (typical for comprehensive ATV service manuals)
Type:
Workshop Service Repair Manual
Format:
Downloadable (typically PDF)
Engine Mechanical:
Top end (cylinder head, valves, camshaft), bottom end (crankshaft, connecting rods, pistons), timing system, lubrication, cooling.
Engine Fuel System:
Carburetor (likely Keihin CVK34 or similar), fuel pump, fuel filter, fuel lines, choke system, idle speed adjustment.
Engine Ignition System:
CDI unit, ignition coil, spark plug, stator, wiring.
Transmission And Drivetrain:
Automatic transmission (PVT - Polaris Variable Transmission), belt replacement and adjustment, clutch system (primary and secondary), gear selection mechanism, drive shafts, differentials (front and rear), CV joints, axle boots.
Brakes:
Hydraulic brake system, brake calipers, master cylinders, brake lines, brake pads, brake fluid specifications and bleeding procedures, parking brake.
Suspension:
Front and rear suspension components, shock absorbers, springs, A-arms, bushings, ball joints, adjustment procedures.
Steering:
Handlebar assembly, steering stem, tie rods, tie rod ends, steering column, wheel alignment specifications.
Electrical System:
Battery, charging system (stator, regulator/rectifier), starter motor, lighting (headlights, taillights, brake lights), ignition switch, electrical diagrams, fuses, relays, wiring harness troubleshooting.
Body And Chassis:
Frame inspection, plastic body panels, seat, fenders, rack system, mounting hardware.
Routine Maintenance:
Oil changes, filter replacements, spark plug checks, air filter cleaning/replacement, chain/belt inspection, lubrication points.
Troubleshooting:
Step-by-step diagnostic procedures for common issues (e.g., starting problems, engine misfires, charging issues, braking issues).
Major Repairs:
Engine rebuilds, transmission overhauls, suspension component replacement, brake system repairs, electrical system diagnostics and repair.
Component Disassembly And Assembly:
Detailed instructions for removing, servicing, and reinstalling major components.
Torque Specifications:
Precise torque values for all critical fasteners.
Schematics And Diagrams:
Wiring diagrams, service diagrams for various systems.
Depth:
Comprehensive, covering all aspects from basic adjustments to complete engine and transmission rebuilds. Suitable for professional technicians and advanced DIY mechanics.
Engine Type:
4-stroke, SOHC, 1-cylinder
Displacement:
375cc to 450cc range (specifically 375cc for earlier 400 models, up to ~401cc or slightly more depending on exact variants and bore/stroke. The 'HO' often implied a slightly tuned or higher output version.)
Bore X Stroke:
Typically around 85mm x 70mm (approximate, for common Polaris engines of this era)
Cooling System:
Liquid-cooled
Horsepower:
Estimated 26-30 HP (depending on specific tuning and model year)
Torque:
Estimated 20-24 ft-lbs (depending on specific tuning and model year)
Fuel Delivery:
Carburetor (likely Keihin CVK34 or similar), with specific jetting and adjustment procedures detailed in the manual.
Recommended Fuel:
Unleaded gasoline, 87 octane or higher.
Oil Type:
Polaris recommends specific synthetic or semi-synthetic ATV engine oil, typically SAE 0W-40 or 10W-40. The manual will specify exact grades and API service classifications.
Oil Capacity:
Approximately 1.7-2.0 US quarts (1.6-1.9 liters) with filter change. The manual will provide precise capacity.
Type:
Automatic Polaris Variable Transmission (PVT) with engine braking.
Drive Modes:
High, Low, Neutral, Reverse, Park.
Optional Types:
N/A for this model; PVT was standard.
Clutch System:
Dual centrifugal clutch system (primary and secondary), with detailed service and adjustment procedures for belt wear, engagement, and disengagement.
Fluid Type:
Polaris specific CVT fluid or equivalent. The manual will specify approved alternatives and capacities for belt drive lubrication.
Atv Safety Standards:
Compliant with ANSI/SVIA standards. Manual will cover safety warnings and operational precautions.
Braking System:
Hydraulic disc brakes (front and rear) providing strong stopping power. Manual details operation and maintenance.
Engine Braking:
Standard feature of the PVT transmission, aids in downhill control. Covered in transmission section.
AWD System:
On-Demand True All-Wheel Drive (AWD) for enhanced traction. Manual explains operation and maintenance.
Handlebars:
Ergonomically designed handlebars with comfortable grips. Manual covers adjustment and maintenance.
Lighting:
Dual headlights, taillight, and brake light for visibility. Manual includes bulb replacement and aiming procedures.
Engine Oil Change:
Every 100 hours of operation or annually, whichever comes first. Manual specifies precise interval based on operating conditions.
Air Filter Service:
Inspect every 25 hours, clean/replace as needed. More frequent service in dusty conditions. Manual provides specific cleaning procedures.
Spark Plug Check:
Inspect and gap every 50 hours or annually. Manual provides correct spark plug part number and gap specification (e.g., NGK CR7HSA or similar).
Transmission Belt Inspection:
Inspect for wear and damage every 100 hours or annually. Replacement recommended based on wear and mileage. Manual provides belt part numbers and inspection criteria.
Engine Oil:
SAE 0W-40 or 10W-40 Synthetic or Semi-Synthetic ATV Oil meeting Polaris specifications. Manual will list exact part number or API classification.
Brake Fluid:
DOT 3 or DOT 4 Hydraulic Brake Fluid. Manual will specify which is recommended and capacity for bleeding.
Coolant:
Polaris Premium Antifreeze/Coolant or equivalent ethylene glycol-based coolant with corrosion inhibitors. Typically a 50/50 mix with distilled water. Manual provides capacity and mixing instructions.
Common Wear Items:
CVT belt wear, ball joint wear, tie rod end wear, wheel bearing wear, spark plug fouling (especially if using incorrect fuel/oil), carburetor jetting sensitivity to altitude/conditions.
Electrical Gremlins:
Potential for minor electrical issues such as loose connections or failing grounds, common in off-road environments. Manual's electrical diagrams are crucial for diagnosis.
Polarise Heritage:
Polaris Industries, founded in 1954, is a prominent American manufacturer known for its leadership in the powersports industry, including ATVs, snowmobiles, and motorcycles. The Sportsman line has been a cornerstone of their ATV offerings for decades.
Sportsman Lineage:
The Sportsman 400 HO is part of the long-standing Polaris Sportsman family, which has consistently evolved to incorporate advancements in suspension, drivetrain, and engine technology. The 'HO' designation often signifies a 'High Output' engine variant, offering improved performance over standard models.
Manufacturing Location:
Typically manufactured at Polaris facilities in the United States.
