1986 Suzuki RM125 Owners Manual

The 1986 Suzuki RM125 is a high-performance 125cc motocross motorcycle featuring a liquid-cooled two-stroke engine, 6-speed transmission, front and rear suspension systems, and advanced chassis design for competitive racing. Below are key sections for safety, features, maintenance, operation, and troubleshooting.

1. Features at a Glance 2. Pre-Ride Inspection 3. Basic Operation 4. Specifications 5. Controls and Instruments 6. Maintenance Schedule 7. Engine Maintenance 8. Chassis Maintenance 10. Storage & Winterization 11. Troubleshooting

Features at a Glance

Key components: Liquid-cooled 125cc two-stroke engine, 6-speed transmission, front telescopic forks, rear monoshock suspension, aluminum swingarm, disc brakes.

Feature	Description
Engine Type	Liquid-cooled, two-stroke single cylinder
Displacement	124cc
Transmission	6-speed constant mesh
Front Suspension	Telescopic forks, air-adjustable
Rear Suspension	Full-floating suspension system
Front Brake	Single disc
Rear Brake	Single disc
Fuel Capacity	2.1 gallons (8 liters)
Dry Weight	194 lbs (88 kg)
Seat Height	36.2 inches (920 mm)

Pre-Ride Inspection

Always perform safety check before each ride.

Check fuel level and fuel/oil mixture ratio (32:1 recommended).
Inspect tires for proper pressure and wear: Front 12-15 psi, Rear 12-15 psi.
Test brakes: Ensure proper lever travel and stopping power.
Check chain tension and lubrication.
Verify all controls operate smoothly: throttle, clutch, brakes.

WARNING! Never operate motorcycle without proper safety inspection. Always wear approved helmet and protective gear.

Basic Operation

Starting procedure and basic riding instructions.

Turn fuel valve to ON position.
Pull choke knob for cold starts.
Kick start firmly while applying slight throttle.
Allow engine to warm up before riding.
Shift through gears smoothly using clutch.

CAUTION! Engine requires proper break-in period. Avoid full throttle operation during first 10 hours of operation.

Specifications

Engine: 124cc liquid-cooled two-stroke single cylinder
Bore x Stroke: 56.0 x 50.6 mm
Compression Ratio: 8.5:1
Carburetor: Mikuni VM34SS
Ignition: CDI electronic ignition
Lubrication: Premix (32:1 fuel/oil ratio)
Transmission: 6-speed, wet multi-plate clutch
Frame: Double cradle steel
Wheelbase: 57.5 inches (1460 mm)
Ground Clearance: 13.0 inches (330 mm)

Controls and Instruments

Handlebar controls: Right side - front brake lever, throttle grip. Left side - clutch lever, choke knob, light switch.

Instrument Panel: Speedometer, tachometer, neutral indicator light, high beam indicator.

Basic Controls: Kick starter, gear shift lever, rear brake pedal, fuel valve, ignition switch.

Maintenance Schedule

Regular maintenance intervals for optimal performance.

Item	Every Ride	Every 6 Hours	Every 12 Hours
Engine Oil	-	-	Change
Air Filter	Check	Clean	Replace if needed
Spark Plug	-	Check/clean	Replace
Chain	Lubricate	Adjust tension	-
Brakes	Check	Adjust	Inspect pads

Engine Maintenance

Two-stroke engine care and maintenance procedures.

Spark Plug: Clean and gap to 0.6-0.7mm regularly.
Air Filter: Clean with filter oil and reinstall properly.
Cylinder: Check compression regularly (120-150 psi normal).
Exhaust: Clean power valve system every 20 hours.
Cooling System: Check coolant level and radiator condition.

Tip: Always use high-quality two-stroke oil and premium unleaded fuel.

Chassis Maintenance

Suspension, brakes, and frame maintenance.

Front Forks: Check oil level and seal condition.
Rear Shock: Adjust preload for rider weight and conditions.
Brakes: Check pad wear and fluid level regularly.
Wheels: Inspect spokes and rim alignment.
Bearings: Grease steering head and swingarm bearings annually.

WARNING! Always support motorcycle securely when performing maintenance.

Storage & Winterization

Proper storage procedures for extended periods.

Drain fuel from carburetor and tank.
Remove spark plug and add teaspoon of oil to cylinder.
Clean and lubricate entire motorcycle.
Inflate tires to maximum pressure and store off ground.
Cover with breathable motorcycle cover.

CAUTION! Never store with fuel in system for more than 30 days.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Hard starting	Fouled plug, stale fuel	Replace spark plug; drain old fuel
Poor performance	Clogged air filter, power valve	Clean air filter; inspect power valve
Overheating	Low coolant, lean mixture	Check coolant level; adjust carburetor
Transmission issues	Low oil, worn clutch	Check oil level; inspect clutch plates
Brake problems	Worn pads, air in lines	Replace pads; bleed brake system

Service: Contact authorized Suzuki dealer for major repairs.

Parts: Use genuine Suzuki parts for optimal performance and reliability.