Polaris Tech Tip: How to Inspect Your Polaris UTV/ATV Air Filter and Intake Plenum

Tech Tip: How to Inspect Your Polaris UTV/ATV Air Filter and Intake Plenum

Your Polaris engine breathes in a massive amount of air to produce power. On the trail, that air is filled with fine "talcum" dust and sand. While the air filter is designed to catch these particles, a poorly seated filter or a crack in the intake plenum can allow "raw" air to bypass the filtration system. This is known as "dusting" an engine, and it is the leading cause of premature engine failure in powersports.

Step 1: The "Dirty Side" vs. "Clean Side" Inspection

Open your airbox and remove the filter element. Before you look at the filter, look at the inside of the airbox itself.

• The Clean Side: Use a bright flashlight to look past where the filter sits, into the intake tube (the "boot") leading to the engine. This area should be clinically clean.
• The Finger Swipe: Swipe a clean finger inside the intake boot. If your finger comes out with even a trace of fine dust, your engine is being "dusted." This means air is leaking past the filter seal or through a hole in the ducting.
• The Result: If you see dust in the "clean side," do not ride the machine. You must find the leak and check your engine's compression immediately.

Step 2: Analyzing the Air Filter Element

Polaris typically uses a high-efficiency pleated paper filter. Unlike foam filters on older dirt bikes, these are not meant to be washed or oiled.

• Light Test: Hold a flashlight inside the filter. If you cannot see light through the pleats, the filter is completely loaded with dust.
• The Seal Check: Inspect the rubber gasket at the end of the filter. If it is torn, hardened, or has "crush marks" from being installed crookedly, it will not seal against the airbox.
• The Result: Replace it with a Genuine Polaris OEM Air Filter. Aftermarket filters often lack the exact micron rating or seal thickness required to protect the tight tolerances of a ProStar engine.

Step 3: Inspecting the Intake Plenum and Boots

The plenum is the plastic "lung" between the airbox and the engine. Over time, heat and vibration can cause the rubber boots to crack or the plastic seams to split.

• Clamp Tension: Ensure the worm-gear clamps holding the intake boots to the throttle body are tight. If a clamp is loose, the engine will suck in dirty air from the engine bay.
• The Water Sign: Look for dried "mud lines" inside the airbox. If you see evidence that water has been halfway up the filter, your oil is likely contaminated, and your filter's paper media has been compromised.

Pro Tip: No Compressed Air!

Never use compressed air to "blow out" a paper air filter. The high pressure creates microscopic holes in the paper fibers that are invisible to the eye but large enough to let engine-killing dust pass right through. If the filter is dirty enough to need blowing out, it’s dirty enough to be replaced!

Protect your engine's internal components. Shop Witchdoctors.com for OEM Polaris air filters, intake boots, and airbox sealing kits today!

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