Air Filter Cleaning – Replacement Guide for 1987 Kawasaki KX80BW

Shop parts for a 1987 Kawasaki KX80BW Dirt Bike.

The 1987 Kawasaki KX80BW is a classic youth motocross bike known for its responsive engine and durable construction. Keeping the air filter clean and properly maintained is critical for this model—dust and debris are the enemy of two-stroke engines, and a neglected air filter will reduce performance and engine life. This guide from MotoSport walks you through proprietary best practices for cleaning and replacing your KX80BW air filter, as well as key model-specific notes.

Why Air Filter Care Matters on the KX80BW

The KX80BW utilizes a dual-stage foam air filter, designed to trap large and fine particles while providing maximum airflow to your engine. Its roomy air box, present only on the 1987 Big Wheel variant, offers increased volume for improved performance, making filter maintenance especially important. The increased air volume also means contaminants can be drawn in more quickly if the filter is neglected. Kawasaki's foam filter design maximizes protection, but only if regularly serviced.

Tools & Supplies You Will Need

  • Foam air filter cleaner (solvent or mild detergent)
  • Air filter oil (specially formulated for foam filters)
  • Rubber gloves
  • Clean rags or paper towels
  • Philips screwdriver or 8mm socket (to remove airbox cover)
  • Replacement air filter (optional, Twin Air or Uni recommended)

How to Remove the Air Filter

  1. Turn off your KX80BW and let it cool completely.
  2. Remove the seat using the seat bolts – the airbox is located directly underneath.
  3. Unscrew and gently lift off the airbox cover.
  4. Unclip or unscrew the air filter retainer cage. Carefully remove the filter, taking note of its orientation.

Cleaning the Air Filter

  1. Gently tap the filter to dislodge loose dirt. Do not twist or wring dry foam filters as this can damage the foam or seams.
  2. Immerse the filter in a bucket of warm, soapy water or use a dedicated foam filter cleaner. Massage gently to work out dirt and old oil.
  3. Rinse until water runs clear. Gently squeeze (never wring) out excess water.
  4. Press dry with clean towels. Allow the filter to dry completely away from direct sunlight.

Oiling the Air Filter

  1. Once dry, saturate the filter evenly with foam air filter oil. Massage the oil into the foam for full coverage, being careful not to leave dry patches. MotoSport recommends using blue or red-dyed filter oils for easy visibility.
  2. Check the seams and sealing surfaces; excess oil can be squeezed out with gloves.

Reinstalling the Air Filter

  1. Inspect the airbox for dust or grit and wipe clean with a damp rag.
  2. Check the air filter retainer cage – ensure it is free from damage and fits snugly inside the filter.
  3. Install the freshly oiled filter, making sure it seats fully against the sealing ring for a dust-tight fit. The KX80BW's thick, flat foam sealing ring must make maximal contact with the airbox for best protection.
  4. Secure the retainer and reinstall the airbox cover and seat.

When to Replace the Air Filter

  • If the foam is torn, stiff, or permanently stained, replace it immediately. Filters for the KX80BW (1986-1990) are readily available and affordable through MotoSport.
  • Best practice is to clean the filter every ride in dusty conditions, or every 2-3 rides in less severe environments.
  • Consider keeping a spare filter ready – swapping a clean, dry filter in between motos minimizes downtime.

Special Notes for 1987 KX80BW Owners

  • The 1987 KX80BW features both standard and Big Wheel configurations; airbox capacity is larger than the standard KX80, demanding extra attention to sealing and maintenance.
  • Pay special attention to the sealing ring and gasket area—a poor seal allows dirt past the filter, risking top-end damage.
  • Some owners also install a filter screen for extra defense against fine sand and silt when riding in harsh conditions.

Regular air filter maintenance will keep your 1987 KX80BW running strong – keep your engine protected and your performance high with MotoSport's trusted cleaning and replacement methods.

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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.