🏷️ Basic Information

Make:

Yamaha

Model:

YZ250

Year:

1997

Engine Type:

2-Stroke

Product Type:

Service Repair Workshop Manual

Model Code Specific:

YZ250 (1997)

👋 Introduction

Segment:

Motocross Competition

Target Audience:

Motocross riders, mechanics, restorers of vintage Yamaha dirt bikes

Competitors 1997:

Honda CR250R, Kawasaki KX250, Suzuki RM250, KTM 250 EXC

Yz250 1997 Highlights:

Powerful liquid-cooled 2-stroke engine, aluminum frame (introduced in prior years), advanced suspension (KYB Speed-Sensitive System front forks), potent disc brakes, aggressive styling.

Value For Owners:

Enables owners to perform all necessary maintenance and repairs, understand the bike's systems, and troubleshoot issues effectively, saving on dealership costs and ensuring optimal performance.

📋 Manual Details

Primary Coverage:

1997 Yamaha YZ250

Secondary Coverage:

Similar years and models (user discretion advised)

Estimated Page Count:

200-300 pages (typical for this model year workshop manual)

Manual Type:

Workshop Manual / Service Repair Manual

Language:

English

Format:

Digital (likely PDF, common for online sales)

📖 Manual Coverage

Engine:

Complete overhaul, tuning, carburetor, ignition, lubrication, cooling

Transmission:

Clutch, gearbox, shifting mechanisms, maintenance, troubleshooting

Chassis Suspension:

Front forks (KYB Speed-Sensitive System), rear shock absorber (Monoshock with adjustable damping), linkage, swingarm, wheel bearings, steering head bearings

Brakes:

Front and rear hydraulic disc brake systems, caliper overhaul, fluid replacement, pad service

Electrical System:

Ignition system, lighting, wiring diagrams, troubleshooting basic electrical faults

Fuel System:

Fuel tank, petcock, carburetor (likely Mikuni VM Series), fuel lines

Cooling System:

Liquid-cooled engine, radiator, hoses, thermostat (if applicable)

Bodywork Frame:

Frame inspection, seat, fenders, fuel tank, body panels

Maintenance:

Routine checks, oil changes, filter cleaning/replacement, chain adjustment, spark plug service, piston ring inspection

Troubleshooting:

Diagnostic guides for common performance issues, starting problems, overheating, electrical faults

Repair Rebuild:

Engine top-end rebuild (piston, rings, cylinder), engine bottom-end inspection, transmission disassembly/assembly, suspension overhaul, brake caliper rebuild

Adjustments:

Carburetor jetting and adjustment, clutch free play, throttle cable slack, suspension settings

Wiring:

Detailed wiring diagrams for electrical components and troubleshooting

Depth:

Comprehensive (covers basic maintenance to full engine and transmission rebuilds, including diagnostic procedures)

📊 Manual Specifications

File Format:

PDF (Portable Document Format)

Searchability:

Likely text-searchable (standard for professionally produced PDFs)

Print Quality:

High-resolution, clear diagrams and text suitable for printing

Binding Type:

N/A (Digital)

Paper Type:

N/A (Digital)

⚙️ Engine Specifications

Engine Type:

Liquid-cooled, 2-stroke, reed valve, YZ Power Valve System (YPVS)

Displacement:

249cc

Bore X Stroke:

67.0 mm x 70.0 mm

Compression Ratio:

8.4:1 (typical, check manual for exact spec)

Carburetor:

Mikuni VM38SS (38mm) constant velocity

Ignition:

CDI (Capacitor Discharge Ignition) with electronic advance

Horsepower:

Approx. 45-48 HP (at crank, typical for this era)

Torque:

Not typically published in owner-focused materials, but significant low-to-mid range grunt.

Fuel Type:

Unleaded gasoline, 91 octane or higher recommended

Premix Ratio:

50:1 with high-quality 2-stroke oil (e.g., Yamalube 2R or equivalent)

🔧 Transmission

Transmission Type:

Constant mesh, 6-speed sequential

Clutch:

Wet, multi-disc, cable-actuated

Gear Ratios:

Specific ratios detailed in manual (e.g., 1st: 2.615, 2nd: 1.933, 3rd: 1.500, 4th: 1.235, 5th: 1.045, 6th: 0.870)

Final Drive:

Chain drive (e.g., 520 O-ring chain)

Transmission Oil Type:

Yamalube SAE 10W-30 API SE or SF (or equivalent motorcycle transmission oil)

📐 Dimensions

Length:

Approx. 2,165 mm (85.2 in)

Width:

Approx. 825 mm (32.5 in)

Height:

Approx. 1,265 mm (49.8 in)

Seat Height:

Approx. 970 mm (38.2 in)

Wheelbase:

Approx. 1,475 mm (58.1 in)

Dry Weight:

Approx. 99 kg (218 lbs)

Wet Weight:

Not officially specified, typically around 110 kg (242 lbs) with fluids.

Fuel Tank Capacity:

8.0 liters (2.1 US gal)

🛡️ Safety Features

Safety Certification:

Not applicable (competition off-road vehicle)

Braking System:

Hydraulic disc brakes front and rear for superior stopping power.

Frame Construction:

Rigid aluminum frame for stability and rider feedback.

💡 Technology Features

Infotainment System:

N/A (Competition motocross bike, no electronic infotainment)

Assistance Features:

N/A (Performance-oriented, no electronic rider aids)

Connectivity Features:

N/A

Engine Management:

Mechanical ignition advance, YPVS (Yamaha Power Valve System) for optimized power delivery across the rev range.

Front Suspension:

KYB Speed-Sensitive System (SSS) cartridge forks with adjustable compression and rebound damping, offering progressive damping characteristics.

Rear Suspension:

Monoshock with adjustable spring preload, compression, and rebound damping (typically a KYB unit).

🔧 Maintenance

Oil Change Transmission:

Every 10-15 hours of riding or annually, whichever comes first. Check for contamination.

Air Filter Cleaning:

After every few rides, or more frequently in dusty conditions.

Spark Plug Replacement:

Every 20-30 hours of riding or inspect as needed. Use NGK BR8ES or equivalent.

Top End Rebuild:

Typically every 50-100 hours for racing, or 100-200 hours for recreational use, depending on riding style and maintenance. Manual provides piston ring wear limits.

Chain Adjustment:

Check and adjust every 5-10 hours of riding. Slack specification typically 20-30mm.

Coolant:

Mixture of distilled water and permanent type antifreeze (ethylene glycol-based) with corrosion inhibitor. Typically 50/50 mix. Capacity approx. 1.2 L.

Brake Fluid:

DOT 4 hydraulic brake fluid.

Typical Wear Items:

Piston rings, clutch plates, wheel bearings, steering head bearings, fork seals, carburetor jets/needles.

Carburetor Tuning:

Can be sensitive to temperature, altitude, and rider preference. Manual provides detailed jetting charts and adjustment procedures.

Ypvs Maintenance:

Requires periodic cleaning and inspection of the exhaust power valve system for carbon buildup and proper operation.

📚 Vehicle History

Yamaha Motorcycles:

Yamaha Motor Corporation has a long and successful history in motorcycle racing, particularly in motocross, with iconic models dating back to the early 250cc two-stroke era.

Yz250 Development:

The YZ250 has undergone continuous development, with key milestones including the introduction of liquid cooling, reed valve induction, YPVS, aluminum frames, and advanced suspension technologies. The 1997 model represents a mature and highly competitive iteration.

Production Era:

The YZ250 model line has been in production for decades, with the 2-stroke version continuing to be popular even with the advent of 4-stroke technology.

Manufacturing Location:

Japan (Primary)

🏆 Awards & Recognition

Motocross Heritage:

The YZ250 line has a storied history of success in professional motocross and supercross, with numerous championships won by factory and privateer riders.

Period Reviews:

Contemporary reviews from 1997 often praised the YZ250 for its strong engine performance, compliant suspension, and well-balanced chassis.