Official Yamaha Enticer 340 & Excel III (1983-1988) Snowmobile Service & Repair Manual

Yamaha Enticer/Excel III 340 Series Service Manual - 1983-1988

This professional service manual provides technical data for the maintenance and repair of the Yamaha 340 series snowmobiles. It includes specific procedures for engine overhauls, fuel system calibration, and chassis alignment to maintain operational integrity. Precise oil pump stroke measurements, specifically the 1.65–1.87 mm maximum stroke setting, are essential for preventing engine seizure and ensuring long-term uptime.

Technical Applicability & Serial Ranges

Standard Track Configuration (Excel III)

• Model ID: 8T7 - Starting Frame Serial: 8T7-121101
• Starting Engine Serial: E338-121101

Long Track Configuration (Enticer L)

• Model ID: 8T9
• Starting Frame Serial: 8T9-111101
• Starting Engine Serial: E338-111101

Critical Performance Benchmarks

• Operational Reliability: Detailed electrical testing for CDI systems and lighting coils prevents field failures.
• Parts Accuracy: Exact dimensions for piston clearances and ring end gaps ensure rebuilds meet factory specifications.
• System Safety: Critical torque sequences for cylinder heads and primary sheaves maintain structural safety during high-stress operation.

Document Metadata

• Manufacturer: Yamaha Motor Corporation
• Document Type: Service Manual
• Page Count: 111 Pages
• Technical Coverage: General, Engine, Carburetion, Power Train, Chassis, Electrical.

Technical Depth & Factory Benchmarks

Calibration procedures rely on precise factory-defined variables. The ignition timing is set to 1.6 mm (0.062 in) B.T.D.C., requiring a dial gauge for accurate measurement. Engine compression is optimized at a 6.5:1 ratio, and the Mikuni B38-34 carburetor uses a #240 main jet as the standard baseline for sea-level operation at typical winter temperatures.

Visual Navigation Aids

The manual utilizes exploded views and schematic diagrams to assist in complex assemblies.

• System Architectures: Exploded views for the Recoil Starter, Flywheel Magneto, and Slide Rail Suspension.
• Electrical Mapping: Full-page wiring diagrams including specific circuits for the EC340G electric start model.
• Mechanical Clearances: Visual guides for measuring track deflection and sheave alignment offset.

Table of Contents

• Chapter 1: General Information (Machine ID, Maintenance Intervals, Special Tools)
• Chapter 2: Engine (Removal, Disassembly, Inspection, Top/Bottom End Assembly)
• Chapter 3: Carburetion (Mikuni Tuning, Cable Adjustments, High Altitude Settings)
• Chapter 4: Power Train (Sheave Alignment, V-Belt, Chain Case, Slide Rail Suspension)
• Chapter 5: Chassis (Steering, Skis, Oil and Fuel Tank Maintenance)
• Chapter 6: Electrical (Ignition System, Lighting, Charging, Electric Starter)
• Chapter 7: Appendix (Technical Specifications, Tightening Torques, Wiring Diagrams)

Operational Limits & Specifications

• Cylinder Bore Standard: 60 mm (2.362 in); Wear Limit: 60.1 mm (2.366 in).
• Piston Skirt Clearance: 0.040–0.045 mm (0.0016–0.0018 in).
• Torque Specifications:
  • Cylinder Head Nuts: 25 Nm (18 ft-lb) Final.
  • Primary Sheave Bolt: 60 Nm (43 ft-lb) Final.
  • Spark Plug: 28 Nm (20 ft-lb).
• Fluid Capacities:
  • Fuel Tank: 22.7 Liters (6 US gal).
  • Oil Tank: 2.4 Liters (2.5 US qt) Yamalube 2-cycle.
  • Chain Case: 400 cm³ (13.5 US oz) SAE #75 or #80 Gear Oil.