🏷️ Basic Information

Make:

Yamaha

Model:

Banshee 350

Year:

1991

Model Code:

YFZ350

Generation Designation:

First Generation (1987-1992)

Vin Prefix:

JY

👋 Introduction

Vehicle Market Segment:

High-performance sport ATV, renowned for its power and agility in its era. Positioned as a recreational and competitive off-road vehicle.

Key Competitors Era:

Competed against other high-performance ATVs of the late 80s and early 90s, such as certain models from Suzuki (e.g., LT250R, LT500R) and Kawasaki (e.g., Tecate-4).

Vehicle Key Selling Points:

Powerful twin-cylinder 2-stroke engine, liquid cooling, 6-speed transmission, long-travel suspension, and sporty chassis design. Its reputation for power and customization potential made it a favorite.

Manual Benefit For Owner:

Empowers owners and technicians to perform professional-level maintenance and repairs, saving on dealership labor costs and ensuring optimal performance and longevity of the vehicle. It's the dealer's primary technical resource.

📋 Manual Details

Systems Covered List:

Page Count:

320+

Manual Type:

Factory Service Manual

Language:

English

Format:

Printed

📖 Manual Coverage

Engine Systems:

Covers the complete 347cc liquid-cooled, 2-stroke, reed-valve, parallel-twin engine, including fuel delivery (carburetors, fuel lines, fuel pump), lubrication (pre-mix or oil injection system details), cooling (radiator, water pump, coolant flow), combustion (spark plugs, ignition timing, compression testing), and exhaust systems.

Transmission Drivetrain Systems:

Details the 6-speed sequential manual transmission, clutch operation (cable adjustment, friction plates), gearbox disassembly and reassembly, drive chain maintenance, and rear axle/hub assembly.

Chassis Suspension Steering:

Includes procedures for front and rear suspension adjustments, fork seal replacement, shock absorber servicing, steering linkage inspection and adjustment, wheel bearing replacement, and tire specifications.

Electrical Systems:

Provides comprehensive wiring diagrams, troubleshooting guides for lighting, ignition, battery, starter, and other electrical components. Covers rectifier/regulator function and CDI unit diagnosis.

Maintenance Procedures:

Includes routine maintenance tasks such as air filter cleaning/replacement, spark plug checks, chain lubrication and adjustment, brake fluid checks, and general lubrication points.

Diagnostic Troubleshooting:

Detailed troubleshooting charts and symptom-based diagnostics for common issues like starting problems, poor performance, overheating, and electrical faults.

Repair Rebuild Procedures:

Step-by-step instructions for engine disassembly, cylinder head and piston replacement, carburetor rebuilding, transmission overhaul, and suspension component repairs.

Installation Adjustment Procedures:

Guidance on proper installation of engine components, carburetor synchronization, clutch cable adjustment, and steering alignment.

Technical Depth Level:

Comprehensive, covering everything from basic maintenance checks to full engine and drivetrain rebuilds. Assumes a certain level of mechanical aptitude and provides detailed technical specifications for precision work.

📊 Manual Specifications

Digital Format Quality:

N/A (Printed Manual)

Print Quality Description:

Professional quality printing with clear diagrams and legible text, designed for durability in a workshop environment.

Binding Type:

Likely perfect bound or saddle-stitched for durability.

Paper Type:

Durable, perhaps coated paper to resist grease and shop grime.

⚙️ Engine Specifications

Engine Type:

2-stroke, Reed Valve, Parallel-Twin

Displacement:

347 cc (21.18 cu. in.)

Bore X Stroke:

64.0 mm x 54.0 mm (2.52 in x 2.13 in)

Compression Ratio:

7.1:1 (typical, may vary slightly by region/revision)

Cooling System:

Liquid-Cooled

Ignition System:

CDI (Capacitor Discharge Ignition)

Lubrication:

Pre-mix or Automatic Oil Injection (check specific model variant)

Horsepower Estimate:

Approx. 45-50 HP (stock, may vary)

Torque Estimate:

Approx. 30-35 lb-ft (stock, may vary)

Carburetor Setup:

Dual Mikuni VM26SS (or similar depending on market variation)

Fuel Type Recommendation:

Unleaded gasoline with octane rating of 87 or higher (recommendation per original manual; often run on higher octane for performance).

Fuel Mixture Ratio:

50:1 (Gasoline to 2-stroke oil for pre-mix, if applicable)

🔧 Transmission

Transmission Type:

6-Speed Sequential Manual

Clutch Type:

Wet, Multi-Plate

Drivetrain:

Chain Drive

Transmission Fluid Type:

Yamalube 10W-30 API SG or similar (check manual for exact specification)

Transmission Fluid Capacity:

Approx. 1.0 L (1.1 US qt) (verify with manual)

📐 Dimensions

Overall Length:

Approx. 70.1 in (1780 mm)

Overall Width:

Approx. 44.7 in (1135 mm)

Overall Height:

Approx. 43.1 in (1095 mm)

Dry Weight:

Approx. 397 lbs (180 kg)

Fuel Capacity:

Approx. 2.4 gal (9.0 L)

Front Suspension Type:

Independent, Double Wishbone, Oil Dampers, Adjustable Preload

Front Suspension Travel:

Approx. 9.1 in (230 mm)

Rear Suspension Type:

Swingarm, Monoshock, Adjustable Preload and Rebound Damping

Rear Suspension Travel:

Approx. 9.5 in (240 mm)

Front Tire Size Oem:

AT21x7-10

Rear Tire Size Oem:

AT20x11-9

Front Wheel Size:

10 x 5.5 AT

Rear Wheel Size:

9 x 8 AT

Bolt Pattern:

4-lug (verify specific offset and spacing)

🛡️ Safety Features

Atv Safety Standards Compliance:

Designed to meet relevant industry safety standards for ATVs of its era, though specific crash ratings as seen in automobiles are not applicable.

Braking System:

Hydraulic Disc Brakes (Front and Rear)

Parking Brake:

Yes (typically located on handlebars or shifter)

Hand Guards:

Standard on many models for rider protection.

Throttle Restricter:

Not typically equipped on performance models like the Banshee; designed for experienced riders.

💡 Technology Features

Infotainment Features:

N/A - This is a sport ATV focused on performance, lacking traditional automotive infotainment systems.

Driver Assistance Systems:

N/A - No electronic driver assistance features.

Connectivity Features:

N/A - No electronic connectivity features.

🔧 Maintenance

Oil Change Interval Transmission:

Refer to manual; typically every 20-40 hours of operation or annually.

Air Filter Cleaning:

Recommended every 10-20 hours of operation or more frequently in dusty conditions.

Spark Plug Check:

Recommended every 10-20 hours of operation or annually.

Chain Lubrication Adjustment:

Recommended every 10-20 hours of operation or after riding in wet conditions.

Coolant Type:

Permanent type antifreeze, 50% solution with distilled water (check manual for specific YAMALUBE coolant recommendation).

Brake Fluid Type:

DOT 3 or DOT 4 Hydraulic Brake Fluid (verify with manual).

2 Stroke Oil Type:

High-quality, air-cooled 2-stroke oil, preferably Yamalube or equivalent (meeting JASO FD or FC standards recommended).

Common Banshee Issues:

Carburetor jetting issues (especially at altitude or with modifications), clutch wear due to aggressive riding, vibration at certain RPMs, potential for overheating if cooling system is not maintained, and reed valve wear.

Electrical Common Faults:

CDI unit failures, stator issues, and rectifier/regulator problems, though less common with proper maintenance.

📚 Vehicle History

Yamaha Atv Legacy:

Yamaha has a long history of innovation in powersports, including pioneering the sport ATV segment with models like the Tri-Z and subsequently the Banshee, which became an icon.

Banshee Development Context:

Developed by combining the engine from Yamaha's popular IT200 off-road motorcycle with the chassis of the YTM200/YTM225 three-wheelers, creating a dominant four-wheel sport ATV.

Initial Production Year:

1987

Production Period For This Manual:

1987-1992 (First Generation); this manual specifically covers the 1991 model.

Manufacturing Location:

Japan

🏆 Awards & Recognition

Model Reputation:

Widely recognized as one of the most iconic and popular sport ATVs ever produced, known for its enduring performance and modification potential.

Enthusiast Rankings:

Consistently ranks high in enthusiast polls for vintage and performance ATVs.

Manual Certification:

Factory certified (original manufacturer documentation).