🏷️ Basic Information

Make:

Yamaha

Model:

YZ85

Model Variant:

YZ85LW (Large Wheel)

Year:

2006

Vehicle Type:

Off-road Motorcycle (Motocross)

Chassis Code:

May vary based on specific VIN, but commonly associated with the 5PA series for this generation

👋 Introduction

Segment:

Entry-level to intermediate motocross competition bike.

Target Audience:

Young motocross riders, aspiring racers, and enthusiasts looking for a competitive and reliable machine.

Key Competitors:

KTM 85 SX, Suzuki RM85, Kawasaki KX85, Honda CR85R.

Engine Type:

Powerful liquid-cooled, 2-stroke, reed-valve inducted engine delivering strong mid-range and top-end power.

Suspension:

Performance-oriented KYB (Kayaba) front and rear suspension systems tuned for motocross conditions.

Chassis:

Lightweight and rigid steel frame designed for agility and stability in racing environments.

Variants:

Available in standard and Large Wheel (LW) configurations to accommodate different rider sizes and preferences.

📋 Manual Details

Primary Coverage:

Comprehensive service, repair, and maintenance for the 2006 Yamaha YZ85 and YZ85LW models.

Secondary Coverage:

Troubleshooting, diagnostics, specifications, electrical system, chassis components, bodywork, and regular maintenance.

Estimated Pages:

Likely in the range of 250-400 pages, typical for a full factory service manual covering two models.

Type:

Factory Service Manual / Repair Manual

Language:

English

Format:

Digital Download (PDF)

📖 Manual Coverage

Engine:

Complete engine disassembly, assembly, inspection, and repair of the two-stroke, liquid-cooled powerplant.

Cooling System:

Radiator, hoses, water pump, thermostat, and coolant specifications.

Fuel System:

Carburetor (Mikuni VM28SH), fuel lines, fuel tank, fuel filter, and settings.

Ignition System:

CDI, ignition timing, spark plug specifications, and troubleshooting.

Transmission:

Clutch operation, gearbox components, shift drum, shift forks, gear inspection, and lubrication.

Chassis:

Frame, sub-frame, swingarm, linkages, and suspension mounting points.

Suspension Front:

KYB (Kayaba) 43mm inverted front fork service, including oil type, level, seal replacement, and compression/rebound adjustments.

Suspension Rear:

KYB (Kayaba) monoshock, linkage system service, shock absorber oil and gas charging, and adjustment procedures.

Brakes Front:

Hydraulic disc brake system, caliper service, master cylinder overhaul, pad replacement, and fluid specifications.

Brakes Rear:

Hydraulic disc brake system, caliper service, master cylinder overhaul, pad replacement, and fluid specifications.

Wheels Tires:

Wheel bearing inspection, spoke tension, tire pressure recommendations, and wheel removal/installation.

Electrical System:

Wiring diagram, lighting system, horn, CDI unit, stator, and troubleshooting electrical faults.

Bodywork:

Removal and installation of plastics, seat, fuel tank, fenders, and graphics.

Maintenance:

Routine maintenance tasks such as oil changes, filter cleaning/replacement, chain adjustment, spark plug inspection, and lubrication.

Troubleshooting:

Systematic diagnostic procedures for common and uncommon problems, including starting issues, engine performance problems, and electrical faults.

Repair:

Detailed step-by-step instructions for component repair and replacement, covering major assemblies and smaller parts.

Rebuild:

Complete engine tear-down and rebuild procedures, including piston, cylinder, crankshaft, and connecting rod replacement.

Adjustment:

Carburetor jetting and adjustment, clutch lever free play, brake lever free play, and suspension settings.

Inspection:

Critical component inspection guidelines for wear, damage, and proper function.

Depth:

Comprehensive: Covers everything from basic maintenance and adjustments to complete engine and chassis overhauls.

Diagnostics:

Advanced diagnostics for engine, electrical, and mechanical systems using specification charts and logical troubleshooting trees.

Specifications:

Detailed technical specifications, torque values, measurements, clearances, and tolerances for all major components.

Diagrams Illustrations:

Extensive use of clear, detailed diagrams, exploded views, and photographs to illustrate procedures and component identification.

📊 Manual Specifications

Format:

PDF

Searchable:

Likely, given it's a digital factory manual, allowing for keyword searching.

Resolution:

High resolution, suitable for clear printing of diagrams and text.

Binding:

Not applicable (Digital Download)

Paper Type:

Not applicable (Digital Download)

⚙️ Engine Specifications

Engine Type:

Liquid-cooled, 2-stroke, reed valve

Displacement:

84.7 cc

Bore X Stroke:

47.5 mm x 47.8 mm

Compression Ratio:

8.7:1 (Typical, may vary slightly)

Carburetor:

Mikuni VM28SH, single

Starting System:

Kick starter

Lubrication:

Pre-mix (2-stroke engine oil mixed with gasoline)

Horsepower:

Approx. 22-24 HP (at crank, typical for this class)

Torque:

Approx. 14-15 Nm (at crank, typical for this class)

Fuel Type:

Unleaded gasoline (91 octane or higher recommended)

Fuel Tank Capacity:

4.4 Liters (1.16 US gallons)

🔧 Transmission

Type:

Constant mesh, 6-speed

Clutch:

Wet, multiple disc

Final Drive:

Chain

Gear Ratios:

Specific ratios will be detailed in the manual, crucial for performance tuning.

Transmission Oil:

Yamalube 2R or equivalent high-performance 2-stroke premix oil, mixed with fuel at specified ratio (typically 40:1 or 50:1).

📐 Dimensions

Length:

1,835 mm (72.2 in) for standard, 1,895 mm (74.6 in) for LW

Width:

750 mm (29.5 in)

Height:

1,135 mm (44.7 in) for standard, 1,145 mm (45.1 in) for LW

Wheelbase:

1,255 mm (49.4 in) for standard, 1,285 mm (50.6 in) for LW

Ground Clearance:

355 mm (14.0 in) for standard, 360 mm (14.2 in) for LW

Dry Weight:

79 kg (174 lbs)

Wet Weight:

Approximately 83 kg (183 lbs) with fluids

Front Tire Size:

70/100-17 (standard) / 70/100-19 (LW)

Rear Tire Size:

90/100-14 (standard) / 90/100-16 (LW)

Front Brake Type:

Hydraulic disc

Rear Brake Type:

Hydraulic disc

🛡️ Safety Features

Safety Standards:

Designed for competitive motocross, subject to track regulations rather than road safety standards.

Braking Performance:

Responsive hydraulic disc brakes front and rear for effective stopping power.

Suspension Control:

Adjustable suspension allows riders to fine-tune for optimal handling and control on various terrains.

Ergonomics:

Designed with rider comfort and control in mind, facilitating a stable riding position.

Frame Integrity:

Robust steel frame provides structural integrity and predictable handling characteristics.

💡 Technology Features

Features:

Not applicable (This is a competition motocross bike, not equipped with infotainment systems).

Features:

Not applicable (This is a competition motocross bike, not equipped with driver assistance features).

Features:

Not applicable (This is a competition motocross bike, not equipped with connectivity features).

🔧 Maintenance

Oil Change Premix:

Continuous mixing with fuel during operation; regular checks of oil level in the reservoir if separate oil injection is present (though 2006 YZ85 is typically premix).

Air Filter Cleaning:

After every few rides or as needed based on conditions (critical for engine longevity).

Spark Plug Inspection:

Every 10-15 hours of riding, or as per manual recommendations.

Chain Tension Adjustment:

Regularly, every 5-10 hours of riding, or as chain stretches.

Suspension Service:

Fork oil change every 20-30 hours, full suspension service annually or as per racing demands.

Engine Rebuild Top End:

Piston and ring replacement typically every 40-60 hours of hard use.

Engine Rebuild Bottom End:

Crankshaft and bearing service recommended every 100-150 hours or if play is detected.

Engine Oil Type:

Yamaha Yamalube 2R or equivalent high-performance JASO FD certified 2-stroke premix oil.

Premix Ratio:

Typically 50:1 (20 ml oil per 1 liter of fuel) or 40:1, consult manual for exact specification.

Coolant:

Yamaha Water Wetter or similar permanent type antifreeze coolant (50% ethylene glycol and 50% deionized water).

Brake Fluid:

DOT 3 or DOT 4 hydraulic brake fluid (refer to manual for specific recommendation).

Fork Oil:

Yamaha Suspension Oil 01 or equivalent fork oil with a viscosity rating of approximately 5W-10W. Specific oil level is critical.

Clutch Wear:

Clutch plates can wear over time with hard use, requiring replacement. Clutch basket and hub wear can also occur.

Suspension Seals:

Fork seals can leak, requiring replacement. Rear shock seals can also deteriorate.

Carburetor Jetting:

Carburetor may require re-jetting due to altitude, temperature, or engine modifications to maintain optimal performance.

Engine Top End:

Piston rings and piston wear are common on high-performance 2-strokes and require periodic replacement for sustained power.

Exhaust Pipe:

The expansion chamber can be prone to dents and damage from impacts on the track, affecting performance.

📚 Vehicle History

Yamaha Legacy:

Yamaha has a long-standing and highly respected history in off-road and motocross racing, known for producing competitive and durable machines.

Yz85 Lineage:

The YZ85 has been a staple in the junior motocross category for many years, consistently evolving to incorporate Yamaha's technological advancements and racing feedback.

2006 Updates:

The 2006 model received updates to suspension settings, minor styling tweaks, and potential refinements to engine performance or carburetion compared to previous years. The introduction or refinement of the LW model also signifies adaptation to market needs.

Manufacturing Location:

Typically manufactured in Japan by Yamaha Motor Corporation.

🏆 Awards & Recognition

Motocross Awards:

The YZ85 platform has consistently been a top contender and widely recommended in its class by motocross publications and racing organizations for its performance and reliability.

Review Scores:

Generally receives high marks for engine power, suspension performance, and handling in rider reviews and industry comparisons.

Racing Compliance:

Meets the specifications for various junior motocross racing series (e.g., AMA, FIM Junior Motocross).