Will Dirt Bike Start Without Air Filter? Don’t do it!


A dirt bike air filter should be checked regularly, ideally every time you ride. Especially if the track is dry and dusty. But I’m a mechanic and I live in the real world, I know many air filters aren’t cleaned when or how they should be. This post has you covered.

A dirt bike will start without an air filter. However, riding a dirt bike without an air filter risks carburetor contamination and engine damage over the longer term.

In this post you’ll learn the risks of riding without an air filter, you’ll learn how to clean and oil an air filter and how often you should do it.

atv air filter

Riding Without Air Filter

A dirt bike will run without an air filter, but doing so risks several critical components. While starting and riding your bike short-term likely won’t hurt it, you should be aware of what’s at risk, and that’s what we cover next.

What components are at risk when riding without an air filter?

You know what your air filter does, its job is to trap all that airborne junk and prevent it from entering the intake system. So what’s the big deal if the engine swallows a little dust? Well short term as you know, probably no real damage. However, riding long term without a filter, especially in dusty conditions risks severe carburetor, intake system, oil contamination, crank bearing wear, and premature cylinder and piston wear.

These are all expensive parts to replace repair.

Although dust looks harmless it actually contains fine particles of silica, which for want of a better description are micro rocks. Now consider a dirt bike throttle cranked wide open…. Yep, all those micro rocks are sandblasting the inside of the carburetor, intake system, and inlet valve seat.

And as you know, that’s just for starters. The fine but hard silica is now like liquid sandpaper inside your engine moving around in the oil and getting into places only oil can reach.

An engine under this type of condition will degrade pretty quickly.

How Often Should I Clean Dirt Bike Filter?

A dirt bike air filter should ideally be inspected every day if you are riding hard in adverse conditions. Otherwise, every month or about every one hundred miles works fine.

Dirt bike air filters last year if cared for correctly. But if when inspecting you find a tear or a split seam, it’s time to replace it. A damaged filter is the same as having no filter at all.

If it’s damaged, replace it ASAP.

How To Clean Dirt Bike Air Filter

Cleaning a dirt bike air filter is one of the easiest bike maintenance jobs ever. It requires very little prep work, effort or materials. All track dirt bikes are foam air filters and are reusable.

If in the unlikely event your bike has a pleated paper filter fitted. They can’t be washed or oiled like a foam air filter. You can use compressed air to clean them but ideally, paper air filter elements should be replaced.

The foam air filter cleaning process looks something like this:

  • Remove air filter – Commonly a tool-less task
  • Prep container – Half fill a container with warm water and dish soap
  • Soak – Place the filter in the container and agitate to release the debris, now allow to soak a while
  • Rinse – Rinse with fresh water, and squeeze dry, careful not to tear or split the foam at the seam
  • Air box clean – Using a damp cloth, clean the air box and clean the air bob drain
  • Dry – Allow the filter to air dry, typically takes about thirty minutes

We’re not finished just yet, we have one more important step – oiling the filter, and that’s what we’ll cover next.

Do Dirt Bike Air Filters Need To Be Oiled?

Yes, an engine that works in dusty conditions will benefit from an oiled air filter. But wow… not every air filter may be oiled. Paper pleated filters as said earlier can not be washed or oiled.

So oiling a filter is only possible if you have a foam filter, which to be fair will cover all dirt bikes and ATVs.

To oil a dirt bike filter like a pro, follow these simple tips:

  • Place clean filter in a large disposable plastic bag
  • Add specialized air filter oil (not regular oil)
  • Message the oil into the filter
  • Remove filter and ring out excess
  • Refit the filter and you’re good to go

Can you use engine oil on an air filter?

Air filter oil is a special oil. It remains sticky and that’s what traps the fine dust particles. It is not cool to use engine oil, transmission oil, or WD40. Using these types of oils may offer some protection but are not up to the job at hand.

You may find the following posts helpful:

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Will dirt bike start without oil?

Dirt bike won’t start after washing

Will dirt bike start with low compression?

John Cunningham

John Cunningham is a certified mechanic and writer on ATVFixed.com. I’ve been a mechanic for over twenty-five years, I use my knowledge and experience to write articles that help fellow gear-heads with all aspects of ATV ownership, from maintenance & repair to troubleshooting.

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