Segment:
Entry-level to mid-range trail riding snowmobile
Competitors:
Competed with models from Ski-Doo (e.g., Safari series), Yamaha (e.g., Bravo series), and Arctic Cat (e.g., Panther series) in its class.
Engine Type:
Fan-cooled, two-stroke engine
Ride Characteristics:
Designed for comfortable trail riding and general recreational use, emphasizing reliability and ease of operation.
Engine Systems:
Engine tune-up, carburetor adjustments, cooling system, lubrication, ignition system, recoil starter
Drivetrain Systems:
Drive clutch, driven clutch (secondary clutch), chaincase, drive axle, track system
Suspension Systems:
Front suspension (IFS if applicable to 400, or conventional telescopic forks), rear suspension (articulated track suspension), shock absorbers, springs
Braking Systems:
Brake system maintenance, adjustment, and component replacement (e.g., hydraulic caliper, brake disc)
Electrical Systems:
Ignition system (CDI, coil, spark plugs), lighting, battery, wiring diagrams
Body Chassis:
Handlebar assembly, steering system, seat, body panels, windshield
Maintenance Procedures:
Regular servicing, lubrication points, track tension adjustment, belt inspection, fluid changes
Repair Procedures:
Engine component overhaul, clutch service, suspension repairs, brake caliper rebuild, electrical component replacement
Troubleshooting:
Diagnostic charts for common performance issues, starting problems, and operational faults
Depth:
Comprehensive mechanical and electrical repair, including disassembly, inspection, and reassembly of major components
PDF Quality:
Likely scanned pages, image quality may vary. Recommend Adobe PDF Reader for optimal display of graphics and images.
Printability:
Printable, allowing users to create physical copies of specific sections or the entire manual.
Binding:
Not Applicable (Digital PDF)
Paper Quality:
Not Applicable (Digital PDF)
Engine Type:
Two-stroke, piston-ported
Cylinders:
Single Cylinder
Cooling System:
Fan-cooled
Displacement:
Approximately 398 cc (actual displacement may vary slightly based on specific engine variant, refer to manual for precise figures)
Horsepower:
Estimated 30-35 HP (at crankshaft, typical for this class)
Torque:
Not specified in product info, but characteristic of a mid-range 400cc fan-cooled two-stroke.
Carburetor:
Single Mikuni VM34 or equivalent (refer to manual for exact model and tuning specs)
Fuel Type:
Unleaded gasoline with appropriate two-stroke oil mixture (e.g., 40:1, check manual for precise ratio and oil specification)
Oil Delivery:
Oil injection system or pre-mix (manual will specify exact system)
Transmission Type:
CVT (Continuously Variable Transmission) Automatic
Clutches:
Drive clutch (primary) and driven clutch (secondary) for automatic gear ratio changes.
Gear Reduction:
Chaincase with helical gears for drive axle reduction.
Chaincase Oil:
Specific gear oil for chaincase (refer to manual for type and capacity, likely SAE 80W-90 or similar).
Overall Length:
Not specified in product info, but typically around 100-110 inches for this era.
Overall Width:
Not specified in product info, but typically around 35-40 inches.
Dry Weight:
Estimated 450-500 lbs (dry weight, without fluids or rider).
Fuel Capacity:
Typically 5-7 gallons (refer to manual for exact capacity).
Storage:
Minimal storage, likely a small under-seat compartment or rear rack.
Safety Standards:
Designed to meet relevant snowmobile safety standards of the era, as dictated by governing bodies.
Throttle Control:
Thumb throttle with governor system for engine speed regulation.
Braking System Type:
Hydraulic disc brake (typically rear-mounted).
Kill Switch:
Engine shut-off switch (lanyard type may not have been standard on all models of this year).
Lighting:
Headlight and taillight for visibility.
Dashboard:
Basic instrumentation, typically including speedometer, engine temperature light (if equipped), and possibly an odometer.
Governor System:
Engine governor to prevent over-revving and ensure controlled acceleration.
Lighting System:
Standard 12V electrical system powering headlights, taillights, and potentially hand/thumb warmers (if factory equipped).
Oil Change Chaincase:
Recommended at the beginning of each season or after a specified number of hours/miles (refer to manual for exact interval).
Spark Plug Inspection:
Regular inspection and cleaning/replacement as needed, particularly before critical riding periods.
Clutch Maintenance:
Periodic inspection of drive and driven clutches for wear, belt condition, and proper engagement/disengagement.
Chaincase Gear Oil:
SAE 80W-90 gear oil (API GL-4 or GL-5 specification recommended, check manual for specific Polaris part number or equivalent).
2-Stroke Oil:
High-quality TC-W3 or API-TD rated two-stroke oil for oil injection or pre-mix, as specified by Polaris. Check manual for specific viscosity and brand recommendations.
Carburetor Fouling:
Common with older two-strokes; requires periodic cleaning and adjustment due to fuel quality and exhaust byproducts.
Clutch Wear:
Drive and driven clutch sheaves can wear over time, affecting performance; belt alignment and condition are critical.
Recoil Starter Issues:
The recoil starter mechanism can wear or break, requiring repair or replacement of the recoil assembly.
Track Tension:
Incorrect track tension can lead to excessive wear on the track, hyfax, and suspension components.
Polaris History:
Polaris is a long-standing American manufacturer known for its pioneering work in snowmobile technology, founded in 1954.
Indy Series:
The Indy series was a core product line for Polaris, known for its versatility and performance across various snow conditions and riding styles. The '400' designation typically indicated an engine size in the 400cc class.
Production Period:
The 1987 model year falls within the late 1980s period of significant snowmobile development, characterized by advancements in suspension and engine technology.
