🏷️ Basic Information

Make:

Yamaha

Model:

SRX 400

Year:

1980

Vehicle Type:

Snowmobile

Chassis Code Prefix:

2M6

👋 Introduction

Market Position:

The 1980 Yamaha SRX 400 was positioned as a high-performance, sporty trail snowmobile, emphasizing speed and agility for its era. It competed in a market segment focused on enthusiast riders looking for an exhilarating experience.

Competitive Analysis:

Competed against other performance-oriented snowmobiles from brands like Ski-Doo, Arctic Cat, and Polaris, which offered similar engine displacements and performance characteristics. The SRX line was known for its advanced engineering and often introduced innovative features.

Key Features:

Powerful 398cc 2-stroke engine, lightweight chassis, advanced suspension design for the time, emphasis on rider comfort and handling, sporty aesthetics.

Engine Type Emphasis:

The high-revving, responsive 2-stroke engine was a hallmark of the SRX series, providing strong acceleration and a thrilling riding experience.

📋 Manual Details

Coverage Areas:

Complete service and repair for the 1980 Yamaha SRX 400 snowmobile.

Page Count:

N/A (Manual content details suggest comprehensive coverage, typical for factory service manuals exceeding 200 pages).

Manual Type:

Service Manual / Repair Manual

Language:

English

Format:

Illustrated (likely printed format, though digital versions may exist).

📖 Manual Coverage

Systems Covered:

Engine (2-stroke, 398cc, single cylinder), Fuel System (carburetion, fuel pump, lines), Ignition System (CDI), Cooling System (air-cooled), Drive System (belt drive, clutch, chaincase), Suspension (front telescopic forks, rear slide rail), Brakes (disc/drum), Electrical System (lighting, ignition, controls), Chassis and Bodywork, Track and Skis, Lubrication, Troubleshooting, Specifications.

Electrical System Details:

Detailed wiring diagrams, stator and ignition coil testing, troubleshooting for lighting, kill switch, and ignition components.

Chassis And Bodywork Details:

Includes procedures for removing and installing body panels, skis, handlebars, seat, and associated hardware.

Track And Skis Details:

Includes instructions for track removal/installation, track tension adjustment, ski alignment, and ski/carbide wear inspection.

Procedures Included:

Detailed disassembly, inspection, repair, reassembly procedures for all major components. Routine maintenance tasks, performance tuning, diagnostic charts, wiring diagrams, exploded views, torque specifications, special tool requirements.

Engine Rebuild Procedures:

Detailed steps for cylinder head removal, piston replacement, ring installation, crankshaft inspection and replacement, bearing replacement, gasket and seal replacement.

Clutch Service Procedures:

Includes inspection, cleaning, roller and spring replacement for both primary (drive) and secondary (driven) clutches, as well as belt replacement and alignment checks.

Suspension Repair Procedures:

Instructions for fork seal replacement, shock absorber servicing (if applicable), ski spindle and ski alignment, and track suspension component checks (bogies, idler wheels).

Technical Depth:

Comprehensive, covering from basic maintenance and adjustments to complete engine rebuilds and major component overhauls. Suitable for both novice mechanics and experienced technicians.

Diagnostic Charts:

Includes symptom-based diagnostic flowcharts to help identify the root cause of common performance issues.

Torque Specifications:

Provides precise torque values for all critical fasteners across all systems.

Special Tools:

Lists any specialized tools required for specific repair procedures, such as flywheel pullers, clutch tools, or specialized gauges.

📊 Manual Specifications

File Format:

N/A (Assumed to be a physical document).

Print Quality:

Fully Illustrated (indicates high-quality diagrams and photographs).

Binding Type:

Typically saddle-stitched or perfect bound for service manuals.

Paper Type:

Durable, often glossy paper to withstand workshop environments and detailed printing.

⚙️ Engine Specifications

Engine Type:

2-stroke

Engine Displacement:

398cc

Engine Configuration:

Single Cylinder

Bore X Stroke:

73.0 mm x 92.0 mm

Cooling System:

Air-cooled

Ignition System:

CDI (Capacitor Discharge Ignition)

Horsepower Approximate:

Approximately 50-60 HP (specific figures varied by tuning and model year updates, but this is a general range for this class).

Torque Approximate:

Approximately 40-45 ft-lbs (specific figures varied and depend on RPM, but this gives a sense of power).

Carburetor Type:

Mikuni VM Series (likely dual carburetors, e.g., VM34SC)

Fuel Type:

Unleaded gasoline (typically 87 octane or higher, pre-mix with oil)

Fuel Tank Capacity:

Typically around 6-7 gallons for this class.

Oil Delivery:

Yamaha Autolube oil injection system or pre-mix

🔧 Transmission

Transmission Type:

CVT (Continuously Variable Transmission) with clutch system

Drive System:

Chaincase (enclosed, oil-lubricated) to track drive

Clutch System:

Primary and secondary clutch system for engagement and variable ratio.

📐 Dimensions

Overall Length Approximate:

N/A (Specific dimensions typically found in manual).

Overall Width Approximate:

N/A (Specific dimensions typically found in manual).

Track Width Approximate:

N/A (Specific dimensions typically found in manual).

Dry Weight Approximate:

Around 350-400 lbs (typical for this class and era).

Gross Vehicle Weight Rating:

N/A (Specific GVWR not usually provided for snowmobiles).

Ski Stance:

N/A (Specific stance details would be in the manual).

🛡️ Safety Features

Safety Ratings:

Not applicable for historical snowmobiles in the modern sense. Emphasis on mechanical reliability and rider awareness.

Active Features:

Handlebar-mounted throttle, brake lever.

Passive Features:

Engine kill switch, tether cord (if equipped from factory or aftermarket), robust chassis construction.

💡 Technology Features

Infotainment System:

N/A (Basic analogue instrumentation: speedometer, tachometer, engine temperature warning light).

Driver Assistance Features:

N/A

Connectivity Features:

N/A

🔧 Maintenance

Service Intervals:

Manual will detail intervals for: Carburetor cleaning/adjustment (hourly/daily/seasonal), Spark plug replacement (seasonal/hours), Drive belt inspection/replacement (seasonal/hours), Chaincase oil change (seasonal), Track tension adjustment (as needed), Suspension lubrication (seasonal), Engine oil (Autolube system check/fill, seasonal).

Spark Plug Specifications:

Typical spark plugs used were NGK BR8ES or equivalent, with specified gap (e.g., 0.7-0.8 mm).

Chaincase Oil Type:

Yamalube Gear Oil (or equivalent SAE 80W-90 hypoid gear oil).

2 Stroke Oil Type:

Yamalube 2-stroke oil (or premium NMMA TC-W3 certified oil for pre-mix/Autolube).

Coolant Type:

N/A (Air-cooled engine).

Brake Fluid Type:

DOT 3 or DOT 4, depending on the brake system used (often drum brakes on older models, some may have had disc).

Known Issues:

Typical issues for this era include carburetor gumming due to fuel storage, drive clutch wear, track ice buildup, suspension component wear (bushings, shocks), and potential crank seal leaks. Manual will provide diagnostic steps.

Tune Up Procedures:

Includes: Ignition timing checks, carburetor synchronisation and jetting, compression testing, idle speed adjustment, drive system clutch engagement checks.

📚 Vehicle History

Brand Heritage:

Yamaha has a long and distinguished history in motorsports, including snowmobiles, motorcycles, and marine products, known for engineering excellence and performance innovation.

Model Evolution:

The SRX line was Yamaha's premier performance snowmobile series. The 1980 model represented an evolution of their earlier SR and SRX models, incorporating advancements in engine technology, chassis design, and suspension to meet the demands of performance riders.

Key Technological Advancements:

Yamaha's SRX models often featured improved chassis rigidity, advanced exhaust tuning for 2-stroke engines, and refined suspension geometry, contributing to their competitive edge.

Production Years:

The SRX 400 model line was produced through the early to mid-1980s, with the 1980 model being a significant iteration.

Manufacturing Location:

Yamaha Motor Corporation, Japan.

🏆 Awards & Recognition

Recognitions:

The SRX line was consistently recognized by enthusiasts and media for its performance and handling capabilities during its production run. Specific awards are not commonly documented for individual model years outside of contemporary reviews.