Segment:
Mid-size utility ATV segment, known for its value and versatility for recreational and light-duty work.
Competitors:
Honda Foreman 400/450, Yamaha Kodiak 400/450, Suzuki KingQuad 400, Kawasaki Prairie 360/400.
Powertrain:
400cc class engine, automatic PVT transmission, shaft drive, optional AWD.
Ride Comfort:
Independent Rear Suspension (IRS) on some variants, comfortable seating position, capable off-road performance.
Manual Utility:
Essential resource for owners seeking to perform maintenance, diagnose issues, and undertake repairs to extend the lifespan and maintain the performance of their ATV.
Engine:
Complete engine overhaul, top-end and bottom-end rebuild, valve adjustments, carburetor service, fuel system diagnosis, lubrication system, cooling system.
Transmission:
PVT (Polaris Variable Transmission) clutch system diagnosis and service, belt inspection and replacement, gear case maintenance, differential service.
Drivetrain:
Shaft drive system, U-joints, driveshafts, rear differential, front differential, AWD system operation and service, CV joint maintenance.
Electrical:
Ignition system, charging system (stator, regulator/rectifier), battery service, starter motor, lighting system, wiring diagrams, sensor testing, troubleshooting electrical faults.
Brakes:
Hydraulic brake system, caliper service, master cylinder service, brake fluid replacement, bleeding procedures, brake pad replacement.
Suspension Steering:
Front and rear suspension components, shock absorber service, ball joint replacement, tie rod end replacement, steering column service, wheel alignment specifications.
Chassis Bodywork:
Frame inspection and repair, body panel removal and installation, seat service, rack and pinion service, skid plate removal.
Fuel System:
Fuel tank service, fuel pump operation, fuel filter replacement, carburetor cleaning and adjustment.
Cooling System:
Radiator service, fan operation, coolant flush and replacement, thermostat service.
Maintenance:
Scheduled maintenance checks, oil changes, filter replacements, spark plug service, lubrication points, chain/belt tensioning.
Troubleshooting:
Diagnostic flowcharts for common problems, symptom-based troubleshooting guides, electrical fault finding.
Repair:
Step-by-step disassembly and reassembly instructions for all major components and systems.
Rebuilds:
Complete engine rebuild procedures, transmission overhaul, differential rebuilds.
Specifications Data:
Torque specifications, clearances, fluid capacities, electrical values, emissions data.
Depth:
Comprehensive coverage from basic owner maintenance to advanced engine and transmission rebuilds, including detailed diagnostic procedures and electrical schematics.
Engine Type:
4-stroke, SOHC, 4-valve, liquid-cooled
Displacement:
375cc - 400cc (exact specification varies slightly by model year and internal Polaris designation)
Bore X Stroke:
Approx. 90mm x 70mm (typical for this class of engine)
Compression Ratio:
Typically around 10.0:1
Horsepower:
Approximately 29-31 HP (at crank)
Torque:
Approximately 24-26 lb-ft (at crank)
Fuel Delivery:
Carbureted (Keihin CV-type carburetor, e.g., CVK34 or similar)
Fuel Type:
Unleaded gasoline, 87 octane minimum
Oil Type:
SAE 20W-50, API SG or higher (check specific manual for exact specification and viscosity index)
Oil Capacity:
Approx. 2.0-2.2 US quarts (with filter change)
Transmission Type:
Polaris Variable Transmission (PVT) with Engine Braking
Drive Modes:
2WD, AWD (On-Demand All-Wheel Drive)
Gear Selection:
High (H), Low (L), Neutral (N), Reverse (R), Park (P)
Optional Transmission:
N/A (PVT is standard)
Clutch System:
Primary and secondary clutch system with drive belt.
Gear Reduction:
Reduction gears within the gearcase for torque multiplication.
Gearcase Oil:
Polaris Demand Drive Fluid (Front Differential) / SAE 80W-90 GL-5 (Rear Gearcase)
Atv Safety Standards:
Meets ANSI standards for recreational ATVs (where applicable).
Braking System:
Hydraulic disc brakes front and rear.
Parking Brake:
Hand-operated parking brake lever, typically engaging rear brake.
Lighting:
Dual headlights, taillight/brake light.
Ergonomics:
Handlebar design for control, comfortable grip, throttle control.
Rollover Protection:
N/A (ATVs are not designed with ROPS; emphasis on rider training and safe operation).
Display Features:
Basic LCD display for speed, RPM, fuel level, odometer, trip meter, AWD indicator, gear selection.
Engine Braking:
Standard feature on PVT transmission for downhill control.
Charging Port:
Optional or standard 12V DC accessory outlet for charging devices.
Initial Service:
First service typically around 20 hours or 1 month for break-in checks.
Engine Oil Change:
Every 100 hours or 6 months.
Air Filter Cleaning:
Every 25-50 hours or as needed based on operating conditions (more frequently in dusty environments).
Spark Plug Replacement:
Every 100-200 hours or 12 months.
Pvt Belt Inspection:
Every 50 hours or 6 months for wear and tension.
Engine Oil:
SAE 20W-50, API SG or higher (Polaris recommends their own branded oils)
Coolant:
Ethylene glycol based antifreeze, 50/50 mix with distilled water.
Brake Fluid:
DOT 3 or DOT 4 brake fluid (verify in manual).
Common Problems:
PVT belt wear/slippage, starter solenoid issues, water pump seal leaks, carburetor jetting for altitude changes, occasional electrical connector corrosion.
Recommendations:
Regular cleaning of air filter, proper belt maintenance, checking electrical connections, and using specified fluids are key to longevity.
Polarisa History:
Polaris Industries Inc. is a well-established American manufacturer known for its snowmobiles, ATVs, UTVs, and motorcycles, founded in 1954.
Sportsman Lineage:
The Sportsman line has been a cornerstone of Polaris's ATV offerings, evolving from earlier models with a focus on comfort, utility, and rider-friendliness.
Production Period:
The Sportsman 400 HO was a popular model throughout the late 2000s, bridging the gap between entry-level and higher-performance ATVs.
Manufacturing Location:
Polaris ATVs are primarily manufactured in the United States (e.g., Roseau, Minnesota; Spirit Lake, Iowa).
