The Definitive Yamaha YBR 125 Maintenance Guide: Specs, Torque Settings & Service Intervals

⚠️ Safety First: Read Before You Wrench

Working on your motorcycle carries inherent risks. Improper maintenance can lead to mechanical failure, injury, or death. Always perform work on a level surface with the engine cool. If you are unsure about a procedure—especially those involving brakes, tires, or steering—consult a professional mechanic or refer to the official Yamaha Service Manual. Wear appropriate eye and hand protection at all times.

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1. Essential Fluid & Capacity Specs

• Engine Oil:

  • Capacity: 1.0L (Drain and refill) / 1.2L (Total capacity if engine is stripped).

  • Type: 10W-40 (Standard) or 20W-50 (Hot climates). Use API SG/JASO MA or higher.

  • Filter: The YBR 125 uses a centrifugal oil strainer screen behind the right-hand crankcase cover. There is no external paper filter.

• Brake Fluid: DOT 4 only.

• Front Fork Oil:

  • Capacity: ~155ml per leg (RE05/RE06 models).

  • Grade: SAE 10W fork oil.

2. Engine & Performance Tuning

• Spark Plug: NGK CR6HSA (Standard) or CR6HIX (Iridium).

  • Gap: 0.6 – 0.7 mm.

• Valve Clearances (Cold Engine):

  • Intake: 0.08 – 0.12 mm.

  • Exhaust: 0.10 – 0.14 mm.

• Idle Speed: 1,300 – 1,500 RPM.

3. Drive & Chassis Specs

• Drive Chain: 428 pitch (118 links).

  • Slack: 20 – 30 mm (measured on the side stand).

• Sprockets: 14T Front / 45T Rear (Standard gearing).

• Tire Pressures (Cold):

  • Front: 25 PSI (1.75 bar).

  • Rear: 29 PSI (2.0 bar) solo / 41 PSI (2.8 bar) with a pillion.

• Tire Sizes:

  • Front: 2.75-18 or 90/90-18.

  • Rear: 90/90-18.

4. Critical Torque Settings

Component	Torque (Nm)	Torque (lb-ft)
Oil Drain Bolt	20 Nm	14.5 lb-ft
Spark Plug	12.5 Nm	9.2 lb-ft
Rear Axle Nut	80 Nm	59 lb-ft
Front Axle Nut	59 Nm	43 lb-ft
Exhaust Studs	10 Nm	7.2 lb-ft

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5. Service Schedule

• Oil Change: Every 3,000 miles (5,000 km). Note: Many owners change at 1,500 miles to keep the small engine healthy.

• Chain Lube: Every 300–500 miles.

• Valve Check: Every 6,000 miles (10,000 km).

• Air Filter: Inspect every 3,000 miles; replace if dirty.