Category:
Performance Motocross Motorcycle (Entry-level to Intermediate)
Key Competitors:
KTM 85 SX, Honda CR85, Suzuki RM85, Kawasaki KX85
Model Positioning:
Yamaha's YZ85 is renowned for its potent two-stroke engine, capable suspension, and race-bred chassis, making it a popular choice for aspiring motocross racers.
General Coverage:
Complete Workshop Service and Repair
Estimated Pages:
200-300 (typical for this type of manual)
Type:
Workshop Repair Manual / Service Manual
Primary Language:
English (FR GER implies French and German language versions may be available for sale or included, but core technical content is typically English for broad distribution)
Delivery Format:
Instant Download (Digital)
Engine Systems:
Top-end rebuild, bottom-end rebuild, carburetor tuning, ignition system diagnostics, cooling system, lubrication system, exhaust system
Drivetrain Systems:
Clutch operation and adjustment, transmission overhaul, gear selection mechanism, chain and sprocket maintenance
Chassis Systems:
Front suspension (forks, damping, seals), rear suspension (shock absorber, linkage, bearings), steering system, frame inspection and repair
Braking Systems:
Front and rear brake caliper service, master cylinder overhaul, hydraulic line inspection, pad replacement, bleeding procedures
Electrical Systems:
Wiring diagrams, lighting system, ignition coil, CDI unit, battery maintenance (if applicable to the model's electrical setup)
Fuel System:
Fuel tank, fuel lines, fuel filter, carburetor model identification and jetting
Maintenance Procedures:
Regular servicing, oil changes, filter replacements, chain lubrication and adjustment, spark plug checks, brake fluid checks
Diagnostic Procedures:
Troubleshooting common starting issues, performance problems, electrical faults, suspension tuning advice
Repair Procedures:
Step-by-step instructions for engine disassembly and reassembly, carburetor rebuild, suspension fork service, brake system repair, clutch replacement
Technical Data Sections:
Torque specifications, engine tolerances, bearing clearances, electrical resistance values, fluid capacities
Depth Of Information:
Comprehensive, covering detailed disassembly, repair, and reassembly of all major motorcycle components. Suitable for intermediate to advanced mechanics.
Engine Type:
Liquid-cooled, 2-stroke, Reed valve induction, YPVS (Yamaha Power Valve System) equipped
Bore X Stroke:
47.5 x 47.8 mm
Compression Ratio:
9.4:1 (Typical for this generation)
Horsepower:
Approx. 22-24 HP (Estimates vary based on tuning and measurement)
Torque:
Approx. 10-12 lb-ft (Estimates vary)
Carburetor:
Keihin PWK28 (38mm slide, 28mm bore) or Mikuni VM28SS (common for this era)
Fuel Type:
Unleaded gasoline, minimum 91 octane recommended. Mix with 2-stroke oil.
Ignition Type:
Digital CDI (Capacitor Discharge Ignition)
Cooling Method:
Liquid-cooled
Lubrication Method:
Premix (Fuel and Oil mixture) or Autolube (Oil injection system)
Recommended Oil:
JASO FD certified 2-stroke engine oil (for premix or autolube)
Display Features:
N/A (Pure performance motocross motorcycle, no infotainment systems)
Electronic Aids:
N/A (Mechanical controls, no electronic rider aids)
Ypvs System:
Yamaha Power Valve System (YPVS) optimizes exhaust port timing for improved power delivery across the rev range.
Oil Change Interval:
Every 10-15 hours of riding, or as per manual for transmission oil.
Air Filter Cleaning:
After every few rides, or more frequently in dusty conditions.
Spark Plug Check:
Every 5-10 hours of riding, or as needed based on performance.
Chain Lubrication Adjustment:
Before every ride, check and adjust as necessary.
Top End Rebuild:
Recommended every 20-40 hours of aggressive riding, depending on conditions and rider.
Fork Oil Type:
Yamalube Fork Oil G10 or equivalent (SAE 10W)
Fork Oil Capacity:
Approx. 498 cc per leg (check manual for exact specification)
Coolant Type:
High-quality engine coolant, 50% ethylene glycol and 50% deionized water.
Common Wear Items:
Clutch plates, piston rings, spark plugs, air filters, chain and sprockets, suspension seals and bushings due to high-stress off-road use.
Carburetor Tuning Sensitivity:
Two-stroke engines, especially those with YPVS, can be sensitive to altitude, temperature, and jetting adjustments.
Yamaha Offroad Legacy:
Yamaha has a storied history in motocross, with the YZ line being a dominant force for decades, known for innovation and performance.
Yz85 Development:
The YZ85 evolved from earlier YZ65 and YZ80 models, with significant updates in engine technology (YPVS), suspension, and chassis design over the years.
Manufacturing Location:
Japan (primarily)
