How to Clean Your Reusable Air Filter (Walker, K&N, and Others)

At Precise Racing Products, we know the dirt doesn’t just stay on the track. In dirt oval racing, your engine breathes in the same grit you’re sliding through—and your air filter is your first line of defense. Whether you're running a Walker, K&N, or similar reusable air filter, keeping it clean is critical to protect your powerplant and maintain peak performance under brutal conditions.

This guide walks you through proper cleaning and maintenance to keep your dirt oval engine running hard and breathing clean.

Why It Matters on the Dirt Track

Unlike street use, dirt oval track racing subjects your intake system to extreme dust, clay, rubber, and debris. A clogged or neglected filter can lead to:

• Reduced horsepower and throttle response
• Engine wear from fine particulate intrusion
• Higher operating temps
• Costly rebuilds

In this environment, you’re not just protecting performance—you’re protecting the motor itself.

When to Clean

In dirt track racing, you should clean your filter after every race night or heat session, especially in dry or dusty conditions. Even if you’re running pre-filters or outerwears, contaminants will build up fast.

If the filter is visibly dirty, stained, or starting to cake—it’s already overdue.

What You’ll Need

• A filter-specific cleaner (like Walker or K&N spray cleaner)
• Low-pressure water (garden hose)
• Pre-filter oil (for oiled gauze filters like K&N)
• A clean workspace (not in the pits!)
• Rubber gloves and a clean towel
• Optional: Spare filter to rotate while one dries

Cleaning Steps for Dirt Track Use

1. Remove and Inspect

Remove the filter from the intake tube and inspect for tears, cracks, or blown seals. If damage is found—replace it immediately. No risks on race day.

2. Apply Cleaner

Saturate the dirty side of the filter with the approved cleaning solution. Let it soak for 10–15 minutes to break up heavy clay, rubber dust, and oil.

Don’t let the cleaner dry on the filter.

3. Rinse Gently

Rinse the filter from the clean side out, using low-pressure water. This flushes out trapped dirt without driving it deeper into the pleats. Repeat as needed until the water runs clean.

Never use high-pressure water or air—it can compromise the filter media.

4. Dry Thoroughly

Let the filter air-dry naturally, indoors, and out of direct sun. This may take several hours or overnight—don’t rush it. A wet filter can trap more dirt and choke airflow.

5. Re-Oil if Required

If your filter is an oiled cotton model (like K&N), apply a light, even coating of air filter oil across each pleat. Let it absorb for 20 minutes, then recheck and touch up any dry areas.

Too much oil can foul sensors and choke airflow—apply sparingly.

6. Reinstall or Store

Reinstall your filter or keep it sealed in a clean bag until race time. If you’re running a pre-filter or outerwear cover, make sure it’s clean or replaced regularly as well.

Bonus Tips for Dirt Racers

• Run a pre-filter cover every time—especially in dry, dusty heats.
• Rotate filters if possible: clean one, race with another.
• Keep extra filter oil and cleaner in your trailer for between-session maintenance.
• Log your cleanings so you’re not guessing on race prep.

Race-Ready Airflow Starts Here

Your engine works overtime on a dirt oval—don’t starve it. Keeping your reusable air filter clean ensures consistent power, longer motor life, and fewer headaches when it’s time to fire off the line.

Got questions about which filter setup is best for your dirt setup? Contact Precise Racing Products—we’re racers too, and we’re here to help you stay one step ahead of the dust.