Air Filter Cleaning – Replacement Guide for 2020 KTM 150SX

Shop parts for a 2020 KTM 150SX Dirt Bike.

Proper air filter maintenance is one of the most important factors in keeping your 2020 KTM 150SX running strong, especially if you tackle dusty tracks or rugged trails. This MotoSport-exclusive guide details the step-by-step process for cleaning – or replacing – your air filter, highlighting unique 150SX features that make the job easier but also demanding careful technique for peak performance.

Accessing the Air Filter

The 2020 KTM 150SX design makes air filter access tool-free, a signature convenience for KTM motocross models from 2016 onward. Locate the single seat bolt below the rear fender. Remove this long bolt (it passes through from side to side), then slide the seat rearward and lift it off. With the seat removed, you'll spot the airbox cover. Pop it off – again, no tools required – for direct access to the air filter assembly. This tool-free system encourages frequent maintenance, reducing excuses for dirty filters, but be mindful of reinstallation to avoid grommet misalignment.

Removing the Air Filter

Grasp the air filter tab and gently pull it away from the cage. The 2020 KTM 150SX air filter sits on a distinctive cage with tabs that hold the filter in position. Release these tabs to slide the filter off the cage. Inspect the cage for cracks or damage, as a compromised cage can let dust or debris into the intake.

Cleaning the Air Filter

  • Choose your cleaner based on the filter oil in use. Biodegradable oils require matching biodegradable cleaners; petroleum-based oils require petroleum emulsifiers. Never use gasoline, as it can degrade the filter glue and foam.
  • Drop the dirty filter in a clean tub with the correct cleaning solution. Gently massage the cleaner through the foam until dirt and oil release completely. Let it soak for roughly 15 minutes to loosen stubborn grime.
  • After soaking, gently rinse the filter inside-out with clean water. Repeat as needed until all dirt and residue are flushed out. Avoid wringing or stretching the filter foam, which can cause tears.
  • Allow the filter to dry completely out of direct sunlight. Direct heat can damage the foam.

Oiling the Air Filter

  • Once dry, apply air filter oil generously, ensuring complete coverage inside and out. Work it in by hand – gloves recommended – to prevent dry spots. Insufficiently oiled filters let dust or sand pass into the engine, risking rapid wear. Over-oiling, however, can restrict airflow. The KTM airbox is designed for high ventilation, so an evenly oiled filter is essential.

Reinstallation – Special Notes for 2020 KTM 150SX

  • Check the filter cage's tabs and ensure proper seating so there are no gaps between filter and airbox lip. The 2020 150SX, like all modern KTMs, relies on precise filter fitment for strong intake protection. Misalignment can result in unfiltered air bypass, a common mistake especially when hurried.
  • Wipe the airbox clean of dust or oil before inserting the filter. If necessary, use a mild contact cleaner on the airbox rim.
  • Install the airbox cover, then slide and bolt the seat in reverse order. Confirm all mounting surfaces are secure.

When to Replace the Air Filter

  • If the filter foam is torn, separating, or permanently stained after cleaning, replace it immediately. The 2020 150SX works best with a fresh filter in peak condition; compromised foam cannot be restored.

Pro Tips for KTM 150SX Owners

  • Stock air filter is typically a Twin Air unit, sized for optimal fit in the 150SX frame. If using aftermarket filters, be sure they're model-specific – generic KTM filters may not seal tightly.
  • Keep a spare filter pre-oiled in a sealed bag for fast swaps between motos or during long, dusty rides.
  • Routine cleaning after every ride in heavy dust, or every 2-3 rides in moderate conditions, is recommended.
  • Failure to maintain the air filter may lead to premature piston, ring, and valve wear – the 150SX's high-strung 2-stroke engine is particularly sensitive to dirt ingestion. Frequent filter checks make a big difference in both performance and longevity.

Maintaining your 2020 KTM 150SX air filter is simple and quick thanks to KTM's smart engineering. Stay proactive and MotoSport will keep you ready for every ride.

Related Shopping Categories

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Shop Intake Parts for a 2020 KTM 150SX 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.