How to Change the Coolant in a 2016 KTM 350EXCF: Step-by-Step Guide

Shop parts for a 2016 KTM 350EXCF Dirt Bike.

Routine cooling system maintenance is critical to keep your 2016 KTM 350EXCF running strong on the trail or track. Precise coolant performance prevents engine overheating and potential long-term damage, especially in this high-compression four-stroke designed for performance and longevity. The KTM 350EXCF features a liquid cooling system with dual radiators and a water pump, using a traditional drain bolt for straightforward coolant service.

What You’ll Need

  • Fresh coolant (compatible with aluminum motorcycle radiators; engine ice and similar are popular)
  • Distilled water (optional, for flushing)
  • 8mm socket/wrench
  • Catching pan or container
  • Funnel
  • Gloves and safety glasses
  • Shop rags
  • Torque wrench (recommended)

Preparation

  • Ensure the engine is completely cool before starting. Removing the radiator cap on a hot motor can cause pressurized coolant spray.
  • Position your bike upright using a stand or center support.

Step 1: Remove the Radiator Cap

  • Locate the radiator cap on the right side, beside the triple clamp. Gently twist it off to relieve pressure and allow draining.

Step 2: Remove the Coolant Drain Bolt

  • The drain bolt is located at the bottom of the water pump cover on the right side of the engine case.
  • Place your catch pan underneath, then use the 8mm socket to remove the bolt. Coolant drains quickly, so be ready with rags for spills.
  • Wait for the system to completely empty. Tilting the bike side to side can help evacuate trapped coolant.

Step 3: Optional—Flush the System

  • If the old coolant is dirty, or you're changing types (e.g., from standard to high-performance), flush the system with distilled water.
  • Reinstall the drain bolt, fill the radiator with distilled water, run the engine briefly, allow it to cool, then repeat the drain process.

Step 4: Reinstall the Drain Bolt

  • Carefully clean the bolt and sealing surface. Reinstall the drain bolt and tighten to factory specification (do not overtighten).

Step 5: Add New Coolant

  • Use a funnel to fill the radiator neck with fresh coolant until the fluid reaches the bottom of the filler neck.
  • On the 350EXCF, it’s possible to trap air in the cooling system. Gently shake or tap the radiators, squeeze hoses, and if the model features a cylinder head bleed screw, briefly loosen it to remove air until coolant escapes.
  • If your bike has an overflow reservoir, fill to the appropriate level marked on the tank.

Step 6: Bleed Air and Top Off

  • With the radiator cap off, start the engine and let it idle for a few minutes; watch the coolant level and add as needed as air escapes.
  • Shut off the bike, allow it to cool, then check coolant level again. Top off if necessary before reinstalling the radiator cap.

MMY-Specific Notes: 2016 KTM 350EXCF

  • The 350EXCF can be susceptible to air pockets after coolant service. Always bleed the system thoroughly for maximum efficiency.
  • Factory fan kits are common on this model. Confirm fan operation after replacement, as some aftermarket coolants can affect sensor performance.
  • Inspect hoses, clamps, and radiator fins for wear, leaks, or debris. The dual radiator setup is robust, but damage or clogging can hinder cooling.
  • Be sure to use only recommended coolant types – silicate and phosphate-free for aluminum systems.

Final Checks and Start-up

  • Verify all bolts and caps are secure.
  • Dispose of old coolant safely according to local regulations—it’s toxic to people and animals.
  • Check coolant level after your first ride, as remaining bubbles may work free.

Keeping your KTM 350EXCF’s cooling system fresh ensures confident performance wherever your trail leads.

Related Shopping Categories

Shop Radiators for a 2016 KTM 350EXCF Dirt Bike.

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Shop Temperature Sensors for a 2016 KTM 350EXCF Dirt Bike.

Shop Tools for a 2016 KTM 350EXCF Dirt Bike.

Shop Radiator Hoses for a 2016 KTM 350EXCF 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.