1987 Polaris Trail Boss 250 Manual PDF

The 1987 Polaris Trail Boss 250 is a rugged ATV designed for trail riding and utility work. This manual covers the 250cc two-stroke engine model with automatic transmission, front and rear suspension, electric start with backup pull start, front and rear racks, and comprehensive maintenance procedures. Below are key sections for safety, specifications, operation, maintenance, troubleshooting, and repair.

1. Features at a Glance 2. Safety Information 3. Specifications 4. Controls and Operation 5. Maintenance Schedule 6. Engine Service 7. Transmission & Drive System 8. Electrical System 9. Brakes & Suspension 10. Troubleshooting 11. Storage & Winterization

Features at a Glance

Key components: 250cc two-stroke engine, automatic Polaris Variable Transmission (PVT), front and rear suspension, front and rear cargo racks, electric start with backup recoil.

FeatureDescription
Engine250cc air-cooled two-stroke single cylinder
TransmissionAutomatic PVT with high/low range and reverse
Starting SystemElectric start with auxiliary recoil backup
SuspensionFront: Independent A-arm; Rear: Swingarm
BrakesFront and rear hydraulic drum brakes
Fuel Capacity3.5 gallons (13.2 liters)
Cargo CapacityFront: 50 lbs; Rear: 100 lbs
Towing Capacity850 lbs maximum
Dry Weight415 lbs (188 kg)
Ground Clearance6.5 inches (165 mm)

Safety Information

Always wear proper safety gear and follow operating guidelines.

  1. Always wear DOT-approved helmet, eye protection, gloves, and protective clothing
  2. Never operate under influence of alcohol or drugs
  3. Inspect ATV before each use for proper operation
  4. Use on designated trails only; avoid paved surfaces
  5. Do not carry passengers - designed for operator only

WARNING! This ATV can be hazardous to operate. Always follow safety guidelines and never exceed your skill level.

Specifications

Controls and Operation

Familiarize yourself with all controls before operation.

Main Controls: Throttle lever, brake lever, ignition switch, transmission range selector (H/L/R), choke, light switch, starter button.

Starting Procedure: Turn fuel valve ON, set transmission to NEUTRAL, apply choke if cold, turn ignition ON, press starter button or use recoil starter. Allow engine to warm up before riding.

Riding: Select appropriate range (High for trails, Low for heavy loads), apply throttle smoothly, use both brakes for stopping, avoid sudden maneuvers.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

ServiceEvery 25 hrsEvery 100 hrsEvery 200 hrs
Engine oil change
Air filter cleaning
Spark plug inspection
Brake inspection
Drive chain adjustment
CVT belt inspection
Wheel bearing service
Suspension lubrication

Engine Service

Two-stroke engine requires proper fuel/oil mixture and regular maintenance.

  1. Fuel Mix: 50:1 ratio - 2.6 oz Polaris 2-stroke oil per gallon of gasoline
  2. Spark Plug: NGK BR8ES, gap 0.024-0.028 inches
  3. Compression Test: Should read 120-150 psi
  4. Carburetor: Clean and adjust annually or if performance issues occur
  5. Cylinder: Inspect for scoring; hone if necessary during rebuild

CAUTION! Always use proper 2-stroke oil - automotive oil will damage engine.

Transmission & Drive System

Polaris Variable Transmission (PVT) provides automatic shifting.

  1. PVT Maintenance: Clean clutch sheaves every 100 hours
  2. Belt Inspection: Check for cracks, wear, glazing - replace if damaged
  3. Drive Chain: Adjust tension to 1-1.5 inches of free play
  4. Gear Oil: Change annually or every 100 hours
  5. Range Selector: Ensure proper engagement in High, Low, and Reverse

Tip: Avoid high RPM operation when stationary to prevent belt damage.

Electrical System

12-volt DC system with battery, starter, and charging system.

Testing: Battery should read 12.6V static, 13.5-14.5V when running.

Brakes & Suspension

Hydraulic drum brakes front and rear with independent suspension.

  1. Brake Adjustment: Self-adjusting; check pedal free play
  2. Brake Fluid: DOT 3 or DOT 4; check reservoir level
  3. Suspension: Check for leaks, damage, proper operation
  4. Wheel Bearings: Repack annually or every 100 hours
  5. Tire Pressure: Front 3.5 psi, Rear 3.0 psi (check when cold)

WARNING! Test brakes before each ride. Replace worn brake components immediately.

Troubleshooting

SymptomPossible CauseCorrective Action
Engine won't startNo spark, fuel issue, compressionCheck spark, fuel flow, compression; clean carburetor
Poor performanceClogged air filter, carb issuesClean air filter, adjust carburetor, check compression
Transmission slippingWorn belt, dirty clutchesInspect belt, clean clutch sheaves, check alignment
Electrical failureDead battery, bad connectionsTest battery, check fuses, clean connections
OverheatingLean fuel mix, cooling fins cloggedAdjust carburetor, clean cooling fins, check oil mixture

Service: Contact authorized Polaris dealer for major repairs.

Storage & Winterization

Proper storage prevents damage during periods of non-use.

  1. Add fuel stabilizer to full tank and run engine for 5 minutes
  2. Change engine oil and filter
  3. Clean entire ATV thoroughly
  4. Remove battery and store on trickle charger
  5. Store in dry, covered location with tires inflated
  6. Cover with breathable fabric to prevent moisture buildup

CAUTION! Do not store with fuel in carburetor - drain or run until empty.

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