Positioning:
The Suzuki RM85 and RM85L were highly competitive entry-level motocross bikes, designed for junior racing classes. They are known for their potent 2-stroke power delivery and agile handling.
Competitors:
Kawasaki KX85, Yamaha YZ85, KTM 85 SX
Engine Performance:
Powerful liquid-cooled 85cc 2-stroke engine with reed valve induction and a sophisticated exhaust power-valve system (Suzuki's trademark 'SEP' or similar) for broad powerband.
Chassis Design:
Lightweight and rigid frame, adjustable high-quality suspension (typically KYB components), and optional larger wheels (RM85L) for taller riders or specific track conditions.
Primary Use:
Enables owners and mechanics to perform all necessary maintenance, repairs, and troubleshooting on the specified RM85/RM85L models.
Engine Systems:
Top end (cylinder, piston, rings, head), bottom end (crankshaft, connecting rod, bearings, crankcase), cooling system (radiator, hoses, coolant), lubrication system (premix, gearbox oil)
Fuel System:
Carburetor (Mikuni VM28SS), fuel tank, fuel lines, fuel petcock, air filter
Intake Exhaust:
Intake manifold, reed valve assembly, exhaust pipe, silencer (muffler)
Transmission Drivetrain:
Clutch (operation, adjustment, replacement), gearbox (shifting mechanism, gears, bearings), drive chain, sprockets
Suspension:
Front forks (KYB USD), rear shock absorber (KYB), linkage system, suspension adjustments
Brakes:
Front and rear hydraulic disc brakes, brake calipers, master cylinders, brake pads, brake fluid
Electrical System:
Ignition system (CDI, spark plug), lighting (if applicable, though typically minimal on competition bikes), wiring diagrams, battery (if applicable), stator, flywheel
Steering Handling:
Handlebars, steering stem, headstock bearings, front wheel alignment
Bodywork Chassis:
Frame, subframe, seat, fuel tank, fenders, plastics, graphics, footpegs
Routine Maintenance:
Pre-ride inspection, chain lubrication and adjustment, air filter cleaning, spark plug inspection, oil level checks (gearbox), cleaning
Engine Overhaul:
Top-end rebuild (piston replacement, ring replacement, cylinder honing), bottom-end overhaul (crankshaft, bearings), engine removal and installation
Fuel System Servicing:
Carburetor cleaning and jetting, fuel filter replacement, fuel tank inspection
Transmission Service:
Gearbox oil change, clutch inspection and adjustment, clutch disc replacement
Suspension Servicing:
Fork seal replacement, fork oil change, shock absorber service, linkage bearing maintenance
Brake System Service:
Brake pad replacement, brake bleeding, caliper service, master cylinder service
Electrical Diagnostics:
Troubleshooting ignition system faults, wiring harness inspection, component testing
Troubleshooting Guides:
Specific fault finding for common issues such as poor starting, loss of power, clutch slippage, suspension problems
Depth:
Comprehensive from basic maintenance to complete engine and chassis rebuilds
Displacement:
84.7 cc (4.98 cu in)
Bore X Stroke:
48.0 mm x 46.8 mm (1.89 in x 1.84 in)
Engine Layout:
Single-cylinder, liquid-cooled, 2-stroke
Compression Ratio:
Approx. 9.2:1 (varies slightly by year/spec)
Ignition:
CDI (Capacitor Discharge Ignition)
Cooling System:
Liquid-cooled with radiator and fan (automatic or manual override on some models)
Horsepower:
Estimated 20-23 HP at peak (specific figures vary by year and dyno testing)
Torque:
Estimated 10-12 lb-ft at peak
Carburetor Model:
Mikuni VM28SS
Fuel Type:
Unleaded gasoline with 2-stroke engine oil premix (typically 32:1 or 40:1 ratio specified by Suzuki)
Fuel Capacity:
Approx. 5.0 Liters (1.3 US gallons)
Overall Length Rm85:
Approx. 1845 mm (72.6 in)
Overall Length Rm85L:
Approx. 1870 mm (73.6 in)
Overall Width:
Approx. 740 mm (29.1 in)
Overall Height:
Approx. 1105 mm (43.5 in)
Wheelbase Rm85:
Approx. 1255 mm (49.4 in)
Wheelbase Rm85L:
Approx. 1280 mm (50.4 in)
Ground Clearance:
Approx. 325 mm (12.8 in)
Seat Height Rm85:
Approx. 850 mm (33.5 in)
Seat Height Rm85L:
Approx. 870 mm (34.3 in)
Dry Weight:
Approx. 77 kg (169.8 lbs)
Curb Weight:
Not typically specified for competition bikes, but would include all fluids.
Front Tire Size:
70/100-17 (RM85), 70/100-19 (RM85L)
Rear Tire Size:
90/100-14 (RM85), 90/100-16 (RM85L)
Wheel Bolt Pattern:
N/A (Axle mounting)
Oil Change Gearbox:
Every 10-15 hours of riding, or more frequently for hard use.
Air Filter Cleaning:
After every few rides, or more often if riding in dusty conditions. Replace filter element as needed.
Spark Plug Inspection:
Every 5-10 hours of riding. Clean or replace as needed.
Top End Rebuild:
Typically recommended between 20-40 hours of hard use, depending on riding style and maintenance. Piston ring replacement may be needed sooner.
Chain And Sprocket Inspection:
Inspect for wear and proper tension before every ride. Lubricate regularly.
Gearbox Oil:
SAE 10W-30 or 10W-40, API SG or higher (e.g., Yamalube, Motul 10W-40).
Coolant:
Mixture of distilled water and high-quality motorcycle anti-freeze (ethylene glycol based), typically a 50/50 ratio. Always check manual for specific type.
Brake Fluid:
DOT 4 hydraulic brake fluid.
2 Stroke Oil:
High-quality synthetic or semi-synthetic 2-stroke racing oil (e.g., Motul 800, Bel-Ray MC-2, Yamalube 2R).
Common Wear Items:
Piston and rings (wear out due to 2-stroke nature), clutch plates (can slip if not maintained), wheel bearings, steering head bearings, suspension seals.
Carburetor Tuning:
Can be sensitive to altitude and temperature changes, requiring proper jetting for optimal performance and engine longevity.
Power Valve System:
Requires periodic cleaning and inspection to ensure proper operation, as carbon buildup can affect performance.
