1988 Suzuki RM 250 Manual

The 1988 Suzuki RM 250 is a high-performance motocross motorcycle featuring a liquid-cooled 249cc two-stroke engine, 43mm conventional forks, full-floating rear suspension, and advanced chassis design for competitive racing. Below are key sections covering specifications, maintenance procedures, troubleshooting, and technical data for proper operation and service.

1. Specifications 2. Maintenance Schedule 3. Engine Service 4. Chassis & Suspension 5. Electrical System 6. Fuel System 7. Troubleshooting 8. Torque Specifications 9. Safety Precautions 10. Warranty Information

Specifications

Technical specifications for the 1988 Suzuki RM 250 motocross motorcycle.

Component	Specification
Engine Type	Liquid-cooled 2-stroke single cylinder
Displacement	249cc
Bore x Stroke	67.0 x 70.8mm
Compression Ratio	8.5:1
Carburetor	Mikuni VM34SS
Ignition	CDI electronic ignition
Transmission	5-speed constant mesh
Front Suspension	43mm conventional telescopic forks
Rear Suspension	Full-floating system with adjustable rebound damping
Front Brake	Single disc 220mm
Rear Brake	Single disc 220mm
Dry Weight	98 kg (216 lbs)
Fuel Capacity	8.5 liters (2.2 gallons)

Maintenance Schedule

Regular maintenance intervals for optimal performance and longevity.

After each race/ride: Check tire pressure, chain tension, brake function
Every 10 hours: Clean air filter, check spark plug, inspect brakes
Every 20 hours: Change transmission oil, check wheel bearings
Every 30 hours: Top end inspection, suspension service
Every 50 hours: Complete engine overhaul recommended

WARNING! Always allow engine to cool before performing maintenance. Use proper safety equipment.

Engine Service

Detailed procedures for engine maintenance and repair.

Top End Rebuild: Remove cylinder head, inspect piston and rings, measure cylinder wear
Carburetor Adjustment: Main jet: #420, Pilot jet: #50, Needle: 6DH6-3
Cooling System: Check radiator fluid level, inspect hoses for leaks
Power Valve: Clean and lubricate Suzuki AETC system every 15 hours
Transmission: Use Suzuki CCI Super Oil or equivalent 2-stroke oil

CAUTION! Engine components become extremely hot during operation.

Chassis & Suspension

Frame: High-tensile steel cradle frame with box-section swingarm
Front Forks: 43mm Showa with 295mm travel, adjustable compression
Rear Shock: Gas-charged with 315mm wheel travel, adjustable preload and rebound
Wheels: Front: 21x1.60, Rear: 19x2.15 Excel rims
Tires: Front: 80/100-21, Rear: 110/90-19
Chain: DID 520VM, 112 links
Sprockets: Front: 13T, Rear: 50T

Electrical System

CDI ignition system specifications and maintenance.

Component	Specification
Spark Plug	NGK BR9ES (gap 0.6-0.7mm)
Ignition Timing	1.8mm BTDC (fixed)
Charging System	AC magneto 60W
Battery	Not applicable - kick start only
Headlight	Not equipped (motocross model)

Fuel System

Fuel mixture and carburetor settings for optimal performance.

Fuel/Oil Ratio: 20:1 during break-in, 32:1 for normal operation
Recommended Fuel: 92 octane premium unleaded
Oil Type: Suzuki CCI Super Oil or high-quality 2-stroke oil
Float Level: 21.5mm ± 1.0mm
Air Screw: 1-1/2 turns out from lightly seated position

Tip: Always mix fuel thoroughly before adding to tank.

Troubleshooting

Common issues and solutions for the 1988 RM 250.

Symptom	Possible Cause	Corrective Action
Hard starting	Fouled plug, improper fuel mix	Replace spark plug, check fuel ratio
Poor performance	Clogged air filter, power valve stuck	Clean air filter, service power valve
Transmission noise	Low oil level, worn gears	Check oil level, inspect transmission
Overheating	Lean jetting, radiator blockage	Check jetting, clean radiator fins
Poor suspension	Worn seals, incorrect oil level	Replace seals, check oil quantity

Torque Specifications

Critical torque values for proper assembly.

Component	Torque Value
Cylinder Head Nuts	22 Nm (16 ft-lbs)
Spark Plug	25 Nm (18 ft-lbs)
Front Axle Nut	65 Nm (47 ft-lbs)
Rear Axle Nut	100 Nm (72 ft-lbs)
Engine Mount Bolts	40 Nm (29 ft-lbs)
Sprocket Nuts	65 Nm (47 ft-lbs)

Safety Precautions

Always wear proper safety equipment including helmet, goggles, gloves, boots, and protective clothing. Never operate motorcycle on public roads. This is a competition vehicle designed for closed-course use only.

WARNING! Motorcycle racing is dangerous. Always ride within your skill level and inspect motorcycle before each use.

Warranty Information

1988 Suzuki RM 250 limited warranty covers defects in materials and workmanship for 30 days from date of purchase for private use. Competition use voids warranty. For service and parts, contact authorized Suzuki dealers. Keep this manual with motorcycle at all times.