Motocross air filter

Your engine sucks thousands of liters of air every lap. If there's excessive dust or mud in that air, your piston will act directly like sandpaper. A high-quality motocross air filter is your only defense to prevent sand from getting into the cylinder, which would cause catastrophic engine damage. What's more, a dirty, saturated filter will immediately lead to noticeable power loss.

At MXProStoreParts, we act as your technical pit crew and don't take any risks. We supply dual-stage foam filters and everything you need for your air filter maintenance from leading brands like Twin Air and Airtime. Don't take chances—use our parts finder to get the perfect fit for your specific filter cage.

Buying a motocross air filter: The key choices

Avoid costly repairs and keep the following in mind when ordering a new filter:

The perfect fit: A filter that leaks will let sand through. Every airbox is unique. Always use the MXProStoreParts Partsfinder to match the filter to your bike's brand and model year.
Pre-oiled or dry: Want to hit the track right away? Choose a 'pre-oiled air filter'. These are already perfectly and evenly coated in oil at the factory.
4-stroke (Fire Resistant): Riding a 4-stroke without a spark arrester in the airbox? Always install a fire-resistant air filter. A backfire from the throttle body will ignite a standard filter immediately.
Dust covers (GP Cover): Riding in bone-dry sand? Fit a dust cover (filterskin) over your filter. Pull it off between motos and you’ll have a clean, fresh filter again.

Step-by-step guide: Washing and oiling your air filter

Once the tracks dry out in spring, the air filter is the most ordered replacement part in our workshop. You should replace (or clean) your air filter after every dusty ride. Our Pitcrew team has these key rules for all foam filters in our range:

Step 1: Use the correct materials (No gasoline!)
Washing your filter? Never use gasoline or turpentine. These products will dissolve the industrial adhesive that holds the foam layers together. Submerge the dirty filter in a bucket of specialized cleaner (such as Twin Air Dirt Remover). Use a bucket with a bottom grate so you don’t wash the filter in its own dirt. Gently squeeze out the dirt. Never wring the filter out — the twisting forces will tear the foam straight apart.

Step 2: Rinse thoroughly and let dry completely
Rinse the filter thoroughly in a bucket of warm water and dish soap. Keep rinsing until the water stays completely clear, so you know all leftover dirt and old oil has been removed. Let the filter dry for a minimum of 24 hours. If the foam is still damp, the new air filter oil will not adhere and unprotected gaps will form.

Step 3: Oil correctly
A dry filter will not block sand. The extremely sticky air filter oil is your actual trapping medium. Submerge the filter in the oil and work it in thoroughly for even distribution.

Pitcrew tip: Put the oiled filter in a clean plastic bag to work the oil in — this will save you from getting very dirty hands. Squeeze out the excess residue until it no longer drips. Let the oil evaporate for a minimum of one day. The thinners must evaporate, otherwise your engine will temporarily run too rich.

Step 4: Pro tip – The sealing rim
Air always takes the path of least resistance. Always apply a generous layer of Twin Air Bio Sealant (or similar filter grease) to the sealing rim that presses against the plastic airbox. This creates a waterproof, durable barrier. Do not use regular assembly grease on the rim — it will melt away from the heat of your engine block.

Hoe vaak moet ik mijn luchtfilter reinigen?

Na elke actieve wedstrijddag of stoffige rit. Rij je onder extreme omstandigheden in droog zand? Dan kan het filtermateriaal al na twee tot drie uur volledig verzadigd zijn. Vervang het tijdig om vermogensverlies te voorkomen.
Welke olie gebruik ik voor een Twin Air filter?

Gebruik uitsluitend speciale filterolie (zoals Twin Air Liquid Power). Deze is extreem kleverig en ontworpen voor schuimfilters. Gewone motorolie is te dun, zakt naar beneden en laat je blok onbeschermd achter.
Hoe weet ik dat mijn luchtfilter aan vervanging toe is?

Een goed onderhouden schuimfilter gaat gemiddeld een half tot een heel cross-seizoen mee. Zodra de poriën van het schuim oprekken en vervormen door het vele wassen, bestel je direct een nieuwe. Brokkelt het schuim af, voelt het permanent stug aan, of laten de lijmnaden los? Gooi het filter dan direct weg.
Kan ik de luchtfilters in het echt komen bekijken?

Ja, dat is geen probleem. Je bent doordeweeks welkom in onze fysieke winkel en werkplaats in Alphen aan den Rijn. We zijn geopend van maandag tot en met vrijdag van 10:00 tot 16:00 uur (woensdag van 09:00 tot 12:00 uur).
What are the shipping costs and delivery times?

For orders over €75, we cover shipping costs within the Netherlands, Belgium and Germany. Otherwise, the standard shipping charge is €5.95. Products in stock are dispatched the same day. If an item is temporarily out of stock, delivery on backorder takes approximately 1 to 2 weeks.
How can I return my order?

You can return your order within 30 days. Email info@mxprostoreparts.com for return instructions, or see our return policy page.