How to Change the Oil in a 1995 Suzuki RM125: MotoSport.com Official How-To Guide

Shop parts for a 1995 Suzuki RM125 Dirt Bike.

Changing the transmission oil in your 1995 Suzuki RM125 is a critical maintenance step to ensure smooth shifting, reduce internal wear, and maximize longevity in your 2-stroke dirt bike. Even for seasoned riders, a refresher on the model-specific process and torque specs can help you avoid common mistakes. This step-by-step guide from MotoSport.com breaks down the procedure with the special considerations every RM125 owner should know.

Tools & Materials Needed

  • 8mm or 10mm Socket Wrench (for drain plug)
  • Torque Wrench (range up to 25 N·m)
  • Oil Drain Pan
  • Clean Funnel
  • Measuring Cup (metric, 1000ml capacity)
  • Clean Shop Rags
  • Rubber Gloves (optional, for cleaner hands)
  • Replacement Crush Washer (recommended, for drain bolt)
  • Transmission Oil: SAE 10W-40, API SF/SG/SH/SJ with JASO MA certification
  • New Oil Filler Cap O-ring (if damaged)

Step-by-Step Process

1. Prep the Bike and Warm Up the Engine

  • Park your RM125 on flat, level ground. Place the bike upright (use a bike stand if available).
  • Start the engine and let it idle for 2–3 minutes to warm the transmission oil. This reduces viscosity, helping old oil and contaminants drain more easily.
  • Turn off the engine and allow the bike to cool just enough for safe handling.

2. Locate the Drain Plug and Filler Cap

  • The drain plug is on the lower underside of the right crankcase. Position your drain pan beneath it.
  • The filler cap is near the top of the right side case. Also note the oil level bolt (check bolt), which you’ll use later.

3. Remove the Filler Cap and Drain Plug

  • Remove the oil filler cap first to allow air in, which helps the oil drain faster.
  • Using your socket wrench, remove the drain plug and let the oil flow out completely. Allow several minutes for all oil to drain.
  • Inspect the drain plug for metal shavings and replace the crush washer if worn.
  • Clean the drain plug before reinstalling.

4. Replace the Drain Plug

  • Once oil has finished draining, reinstall the drain plug and torque to 21 N·m (2.1 kgf·m, 14.5 lb-ft) for the RM125.

5. Add Fresh Oil

  • Pour 750 ml (0.8 US qt) of SAE 10W-40 transmission oil into the filler hole using a funnel for accuracy and to avoid spills.
  • If you performed an overhaul, fill to 800 ml (0.85 US qt) as specified by Suzuki for this year and model. For regular oil changes, stick to 750ml.

6. Check Oil Level

  • Reinstall the filler cap snugly.
  • Run the engine for 2–3 minutes, then shut down and allow oil to settle.
  • Remove the oil level bolt (just below the filler plug on the clutch cover). If oil seeps out slightly, the level is correct. If not, add oil slowly until oil appears at the bolt opening.
  • Torque the level bolt to 5.5 N·m (0.55 kgf·m, 4.0 lb-ft) and reinstall the filler cap tightly.

7. Wipe Down and Inspect

  • Wipe up any spilled oil. Inspect for leaks at the drain plug and filler cap area.
  • Dispose of the old oil properly at a recycling center or auto parts store.

Model-Specific Callouts: 1995 Suzuki RM125

  • Always use oils that meet API SF/SG/SH/SJ with JASO MA specification for maximum clutch and gear performance.
  • Check for a crush washer on the drain plug. Replace it each oil change to prevent leaks.
  • Never over-tighten the drain plug or oil level bolt—use a torque wrench.
  • The oil level check bolt is on the right-hand side of the crankcase below the oil fill cap. It should take a 10mm socket or Phillips head; if your model does not match, consult your owner’s manual for exact placement and spec.
  • If oil appears milky or contaminated, stop and diagnose possible clutch or seal issues before refilling.

Quick Reference Chart for 1995 RM125

  • Transmission Oil Capacity (Change): 750 ml
  • Transmission Oil Capacity (Overhaul): 800 ml
  • Oil Drain Plug Torque: 21 N·m (14.5 lb-ft)
  • Oil Level Bolt Torque: 5.5 N·m (4.0 lb-ft)
  • Recommended Oil: SAE 10W-40, API SF/SG/SH/SJ with JASO MA

Final Notes

  • Always double-check your owner’s manual for specific torque and procedure details for your exact VIN if your RM125 has suspected modifications.
  • For fresh OEM gaskets, O-rings, quality oils, and other supplies, shop direct from MotoSport.com—your trusted resource for all things dirt bike maintenance.

Regular oil changes are the lifeblood of any 2-stroke. Protect your investment and performance with trained precision—ride safely, and ride MotoSport.com.

Related Shopping Categories

Shop Motor Oil for a 1995 Suzuki RM125 Dirt Bike.

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Shop Oil Drain Pans for a 1995 Suzuki RM125 Dirt Bike.

Shop Tools for a 1995 Suzuki RM125 Dirt Bike.

Shop Oil Fillers and Drain Plugs for a 1995 Suzuki RM125 Dirt Bike.

Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your motorcycle's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.