Market Position:
The Suzuki RM85 is a highly regarded entry-level to intermediate motocross bike, known for its potent two-stroke engine, agile handling, and competitive performance. It competes in the highly popular 85cc class against models from Yamaha, Kawasaki, and KTM.
Competitive Analysis:
The RM85 distinguishes itself with a powerful liquid-cooled engine and a robust chassis designed for demanding motocross tracks. The availability of a 'Big Wheel' (RM85L) version further broadens its appeal to larger or more experienced young riders.
Key Features:
Potent 85cc two-stroke engine, liquid cooling, strong chassis, capable suspension, reliable braking system, and the availability of a Big Wheel variant for increased rider comfort and capability.
Engine:
Complete disassembly, inspection, repair, and reassembly of the 85cc two-stroke engine, including top-end (cylinder, piston, rings, head), bottom-end (crankshaft, connecting rod, bearings), crankcase, and cooling system.
Transmission:
Inspection, maintenance, and repair of the gearbox, clutch, and shift drum mechanism.
Chassis And Suspension:
Front fork (USD telescopic forks) overhaul, seal replacement, fluid changes, and adjustment; rear shock absorber service and linkage maintenance.
Fuel System:
Carburetor (Mikuni VM series) tuning, jetting, cleaning, overhaul, and troubleshooting; fuel tank and line maintenance.
Ignition System:
CDI ignition system, magneto, stator, and spark plug diagnosis and replacement.
Cooling System:
Radiator, hoses, and coolant specifications for the liquid-cooled engine.
Brakes:
Front and rear disc brake system maintenance, including pad replacement, fluid bleeding, and caliper service.
Electrical System:
Wiring diagrams, battery maintenance, lighting, and charging system (rectifier) components.
Bodywork And Plastics:
Removal, installation, and maintenance of body panels, fenders, and seat.
Maintenance:
Regular scheduled maintenance, including oil changes, filter cleaning/replacement, spark plug checks, chain lubrication, and bolt torque checks.
Troubleshooting:
Comprehensive troubleshooting guide for common problems such as starting issues, poor performance, electrical faults, and cooling system leaks.
Rebuilds:
Detailed step-by-step procedures for complete engine teardown and rebuild, including specialized procedures for two-stroke engines.
Adjustments:
Carburetor mixture and idle adjustments, clutch lever free play, brake lever free play, and suspension settings.
Installation:
Guidance on installing various components, from minor parts to larger assemblies.
Technical Depth:
Expert-level detail covering complete engine overhauls, transmission rebuilds, and in-depth diagnostic procedures. Includes detailed torque specifications for all critical fasteners and internal engine components.
Engine Type:
Liquid-cooled, 2-stroke, Reed valve, single-cylinder
Displacement:
85 cc (5.18 cubic inches)
Bore X Stroke:
48.0 mm x 46.8 mm (1.89 in x 1.84 in)
Carburetor:
Mikuni VM28SS
Lubrication:
Pre-mix (Fuel/Oil mixture - specified ratio typically 20:1 or 32:1 depending on oil type)
Horsepower:
Approx. 20-23 HP (Manufacturer's rating varies slightly by year and tuning)
Fuel Type:
Unleaded gasoline
Fuel Octane Rating:
91 octane or higher recommended
Dry Weight:
Approximately 72 kg (159 lbs)
Wet Weight:
Approximately 77 kg (170 lbs) (estimated)
Fuel Tank Capacity:
5.0 Liters (1.3 US gallons)
Front Suspension Type:
Inverted telescopic, coil spring, oil damped
Front Fork Travel:
275 mm (10.8 inches)
Rear Suspension Type:
Swingarm type, linkage system, coil spring, oil damped
Rear Shock Travel:
277 mm (10.9 inches)
Front Wheel Size:
17 inches
Rear Wheel Size:
14 inches (Standard RM85) / 16 inches (RM85L Big Wheel)
Front Tire Size:
70/100-17 40M
Rear Tire Size:
90/100-14 49M (Standard RM85) / 90/100-16 54M (RM85L Big Wheel)
Wheelbase:
1240 mm (48.8 inches)
Overall Length:
1750 mm (68.9 inches)
Overall Width:
750 mm (29.5 inches)
Overall Height:
1070 mm (42.1 inches)
Seat Height:
850 mm (33.5 inches)
Ground Clearance:
330 mm (13.0 inches)
Safety Ratings:
N/A (Motorcycles are not subject to the same structured safety ratings as cars. Emphasis is on rider protection through equipment.)
Active Safety Features:
Responsive braking system (front and rear disc brakes), agile handling, effective suspension for maintaining control.
Passive Safety Features:
Durable frame construction, protective bodywork. Rider is responsible for personal protective equipment (helmet, goggles, armor).
Engine Oil Change Interval:
N/A (2-stroke, premix fuel/oil)
Transmission Oil Change Interval:
Refer to manual for specific hours/miles, typically after every few races or a set number of operating hours. Check manual for specific Suzuki recommendation.
Air Filter Cleaning Interval:
Frequent cleaning recommended, especially after dusty rides. Check manual for specific recommendations based on operating conditions.
Spark Plug Replacement Interval:
Check and clean per manual; replacement typically based on hours of use or condition.
Engine Oil Type:
High-quality 2-stroke engine oil for premix application. Consult manual for Suzuki's specific recommendations (e.g., JASO FD, API TC standards).
Transmission Oil Type:
Suzuki Gear Oil (or equivalent SAE 80W hypoid gear oil). Refer to manual for specific part number and capacity. Capacity typically around 0.6-0.7 liters.
Coolant Type:
High-quality permanent type antifreeze coolant (ethylene glycol-based), mixed with distilled water in a 50/50 ratio. Check manual for specific Suzuki recommendations.
Common Issues:
Like most high-performance 2-stroke motocross bikes, potential issues can include premature piston/ring wear if not properly maintained or if run lean, clutch wear from aggressive use, and fork seal leaks if subjected to harsh terrain or impact. Overheating can occur if coolant levels are low or the radiator is blocked.
Brand Heritage:
Suzuki has a long and storied history in motorcycle racing, particularly with its RM line of motocross bikes, known for performance and durability.
Model Evolution:
The RM85 has been a staple in Suzuki's mini-motocross lineup for many years, with its design evolving to incorporate advancements in engine technology, suspension, and chassis dynamics to remain competitive in the youth racing segment.
Production History:
The RM85 was produced continuously from its introduction until a brief hiatus for the 2010 and 2011 model years, with production resuming for 2012. This manual covers the generation that saw significant updates and remained largely consistent through the production run.
