Positioning:
High-performance sport ATV, renowned for its power and aggressive styling.
Competitors Historical:
Suzuki LT250R, Honda TRX250R, Kawasaki Mojave 250
Engine Characteristics:
Powerful V-twin, two-stroke engine offering significant horsepower and torque.
Handling:
Agile handling and suspension designed for off-road performance.
Dual Carburetors:
Separate carburetors for each cylinder contribute to optimal power delivery.
Purpose:
To provide comprehensive instructions for maintenance, repair, and overhaul, enabling technicians and owners to service the YFZ350 effectively.
Value:
Empowers users to perform professional-level maintenance and repairs, saving time and money while ensuring optimal vehicle performance and longevity.
Engine:
Complete Engine Tune-up, Removal, Installation, Disassembly, Reassembly, Performance Tuning
Transmission:
Transmission Removal, Installation, Disassembly, Reassembly, Gearbox Servicing
Fuel System:
Carburetor Servicing and Tuning, Fuel Tank, Fuel Lines, Fuel Pump Operation
Ignition:
Ignition System Diagnostics, CDI Unit, Spark Plugs, Timing
Lubrication System:
Oil Pump Operation, Premix Ratio (if applicable), Lubrication System Maintenance
Exhaust:
Exhaust System Components, Pipe Servicing, Silencer Maintenance
Electrical System:
Wiring Diagrams, Lighting, Starting System, Charging System, Electrical Component Diagnosis
Bodywork:
Body Panel Removal, Installation, Fairings, Seat, Handlebars
Suspension:
Front and Rear Suspension Servicing, Shock Absorber Adjustments, Bushings
Brakes:
Brake System Overhaul, Pad Replacement, Fluid Bleeding, Disc Servicing
Cooling System:
Radiator Servicing, Coolant Exchange, Thermostat Operation
Wheels And Tires:
Tire Maintenance, Wheel Bearing Servicing, Rim Inspection
Maintenance:
Routine Service, Tune-ups, Filter Replacements, Fluid Changes
Repair:
Component Repair, Assembly/Disassembly Procedures, Troubleshooting Guides
Diagnostics:
Fault finding for various systems, diagnostic flowcharts
Overhaul:
Complete engine, transmission, and component rebuild procedures
Special Tools:
Identification and usage of Yamaha-specific tools for various procedures
Depth:
Comprehensive; suitable for professional technicians and advanced DIY enthusiasts
Diagnostic Focus:
Detailed troubleshooting steps for common and complex issues
Rebuild Detail:
Step-by-step instructions for complete engine and component rebuilds
Engine Code:
350cc V-twin (specific code varies by internal Yamaha designation)
Bore X Stroke:
64.0 mm x 54.0 mm
Compression Ratio:
7.1:1 (typical for this era, subject to manual confirmation)
Ignition System:
CDI (Capacitor Discharge Ignition)
Cooling Method:
Liquid-cooled
Horsepower Approx:
50-55 HP (estimated, subject to specific tuning and regulations)
Torque Approx:
30-35 lb-ft (estimated)
Carburetors:
Dual Mikuni VM26SS
Fuel Type:
Unleaded gasoline (minimum 87 octane recommended, refer to manual for precise specification)
Premix Ratio:
50:1 (Yamalube 2-stroke oil or equivalent, consult manual)
Length:
Approximately 1855 mm (73.0 in)
Width:
Approximately 1120 mm (44.1 in)
Height:
Approximately 1040 mm (40.9 in)
Wheelbase:
Approximately 1280 mm (50.4 in)
Dry Weight:
Approximately 175 kg (386 lbs)
Fuel Capacity:
Approximately 10.0 Liters (2.6 US gallons)
Front Travel:
Approximately 230 mm (9.1 in)
Rear Travel:
Approximately 240 mm (9.4 in)
Atv Safety Standards:
Adherence to applicable safety standards for ATVs of the era.
Brakes:
Hydraulic disc brakes front and rear for strong stopping power.
Throttle Limiter:
Potential for aftermarket or early models to have adjustable throttle limiters (manual would cover standard configuration).
Hand Guards:
Standard on many models for hand protection.
Manual Emphasis:
Manual highlights WARNING, CAUTION, and NOTE for critical safety and procedural information.
Infotainment System:
N/A (Basic instrumentation: speedometer, odometer, neutral indicator, high-beam indicator, coolant temperature warning light).
Driver Assistance Features:
N/A (Focus is on rider control and mechanical feedback).
Connectivity Features:
N/A
Oil Change Transmission:
Refer to manual for specific mileage/hours interval (typically every 6 months or 100 hours of use)
Air Filter Cleaning:
Frequent cleaning recommended, especially in dusty conditions (refer to manual for specific intervals)
Spark Plug Check:
Check and gap spark plugs regularly, as per manual recommendations (e.g., every 20-30 hours)
Chain Lubrication Adjustment:
Lubricate and adjust chain tension regularly (refer to manual for frequency and specifications)
Carburetor Cleaning:
As needed or as per manual recommendation, especially if performance issues arise.
Engine Oil Type:
Yamaha 2-M 10W-40 or equivalent API Service SE, SF, SG type 2-stroke motor oil (for premix). For gearbox, refer to transmission oil specs.
Coolant Type:
Yamaha High Performance Coolant or equivalent permanent type antifreeze (ethylene glycol based). Refer to manual for mixture ratio.
Carburetor Fouling:
Common due to two-stroke nature; requires regular cleaning and proper jetting.
Top End Wear:
Can occur with heavy use; regular maintenance of piston rings and cylinder is crucial.
Cooling System Leaks:
Inspect hoses and radiator for leaks and proper coolant levels.
Electrical Connections:
Ensure all electrical connections are clean and secure to prevent intermittent issues.
Yamaha Motorsports Legacy:
Yamaha has a long-standing history of excellence in motorsports, including dirt bikes and ATVs, known for their performance-oriented engineering.
Yfy350 Banshee Introduction:
Introduced in 1987 as a groundbreaking, high-performance sport ATV, combining a powerful twin-cylinder two-stroke engine with a lightweight chassis.
1997 1998 Updates:
While specific major revisions between '97 and '98 might be minor, this period represents the refinement of the initial design, focusing on reliability and performance enhancements.
Production Years Overall:
1987 - 2006 (in North America)
