1987 Ski Doo Safari 377 Service Manual

The 1987 Ski Doo Safari 377 is a classic snowmobile featuring a 377cc two-stroke engine, oil injection system, slide rail suspension, and electric start. This service manual provides comprehensive technical information for maintenance, troubleshooting, and repair procedures. Below are key sections covering specifications, maintenance schedules, engine service, electrical systems, chassis, and troubleshooting.

1. Specifications 2. Maintenance Schedule 3. Engine Service 4. Fuel System 5. Electrical System 6. Drive System 7. Suspension & Steering 8. Brake System 9. Troubleshooting 10. Torque Specifications 11. Wiring Diagrams

Specifications

Technical specifications for the 1987 Ski Doo Safari 377 snowmobile.

Component	Specification
Engine Type	377cc two-stroke, fan-cooled
Bore x Stroke	72mm x 72mm
Compression Ratio	7.2:1
Fuel System	Oil injection with 32mm Mikuni carburetor
Ignition System	CDI electronic ignition
Starting System	Electric start with pull start backup
Track Dimensions	15 x 121 inches
Drive System	Borg-Warner silent chain
Suspension Front	Double A-arm with springs
Suspension Rear	Slide rail with torsion springs

Maintenance Schedule

Recommended maintenance intervals for optimal performance.

Pre-season inspection: Check all systems before first use.
Every 500 miles: Change engine oil, inspect drive belt.
Every 1000 miles: Replace spark plugs, check carburetor adjustment.
Every 2000 miles: Inspect track and suspension components.
Seasonal: Fog engine for storage, check battery charge.

WARNING! Always disconnect battery before performing maintenance. Use proper safety equipment.

Engine Service

Engine maintenance and repair procedures.

Spark plug replacement: Use NGK BR9ES gapped at 0.020 inches.
Compression test: Should read 120-140 PSI per cylinder.
Cylinder head removal: Torque to 18 ft-lbs when reinstalling.
Piston replacement: Measure ring end gap (0.010-0.020 inches).
Carburetor adjustment: Main jet 180, pilot jet 40, needle clip 3rd position.

CAUTION! Engine must be cool before disassembly. Use new gaskets during reassembly.

Fuel System

Carburetor: Mikuni VM32 with choke and throttle cable adjustment.
Fuel Pump: Pulse-operated diaphragm type.
Oil Injection: Separate oil tank with injection pump.
Fuel Filter: In-line replaceable filter element.
Fuel Lines: Check for cracks and replace if hardened.

Electrical System

Electrical components and testing procedures.

Battery: 12V 18Ah, maintain charge during storage.

Stator: Output 200W AC, test resistance between terminals.

CDI Unit: Check for spark if engine won't start.

Voltage Regulator: Maintains 13.5-14.5V charging voltage.

Lights: Headlight 55/60W, tail light 5W, check grounds.

Drive System

Drive train maintenance and adjustment.

Drive belt inspection: Check for cracks and proper width (1-3/8 inches).
Chain case: Check oil level and adjust tension.
Secondary clutch: Clean sheaves and check spring tension.
Track adjustment: Set tension to 1 inch deflection at center.
Drive sprockets: Check for worn teeth and replace if necessary.

Tip: Always support sled securely when working underneath.

Suspension & Steering

Front and rear suspension components.

Front suspension: Check A-arm bushings and ball joints.
Shock absorbers: Inspect for leaks and proper damping.
Steering linkage: Check for play in tie rods and steering column.
Rear suspension: Inspect slide rails and idler wheels.
Spring adjustment: Set for rider weight and conditions.
Ski alignment: Set toe-in to 1/8 to 1/4 inch.
Ski carbides: Replace if worn below 1/4 inch.
Limiter straps: Adjust for desired ski pressure.

WARNING! Always use proper jack stands when lifting sled.

Brake System

Mechanical brake maintenance and adjustment.

Brake Pad: Replace if thickness below 1/8 inch. Brake Cable: Adjust for proper lever travel. Brake Drum: Clean and inspect for scoring.

Troubleshooting

Common problems and solutions.

Symptom	Possible Cause	Corrective Action
Engine won't start	Fuel, spark, or compression	Check fuel flow, spark plug, compression test.
Poor performance	Carburetion or exhaust	Clean carburetor, check exhaust restrictions.
Electrical failure	Battery or connections	Test battery voltage, clean connections.
Track slipping	Belt or clutch issues	Inspect drive belt, check clutch operation.
Overheating	Cooling system	Check cooling fins, fan operation.

Reset: Disconnect battery to reset electrical system if needed.

Service: Contact authorized Ski Doo dealer for complex repairs.

Torque Specifications

Critical torque values for assembly.

Cylinder Head Bolts: 18 ft-lbs
Spark Plugs: 18 ft-lbs
Drive Clutch Bolt: 65 ft-lbs
Axle Nut: 80 ft-lbs
Engine Mount Bolts: 25 ft-lbs
Ski Spindle Nuts: 45 ft-lbs
Track Adjustment Bolts: 15 ft-lbs
Chain Case Cover: 8 ft-lbs

Wiring Diagrams

Complete electrical schematics for troubleshooting.

Refer to pages 45-48 in printed manual for full-color wiring diagrams. Main components include: ignition switch, CDI unit, stator assembly, voltage regulator, lighting circuits, and starting system.

CAUTION! Disconnect battery before working on electrical system.