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K&N Air Filter KRK-3942, image 1

K&N

K&N Air Filter KRK-3942

Air FiltersSKU KNRK3942

Cheapest we found

$403.95

at XPERT Moto Gear

$403.95 lowest$431.99 highest

7 recent in-stock prices · spread $28.04 (7%)

Based only on in-stock prices checked in the last 30 days. 7 stores checked; dates for every store are shown below.

Recorded store prices

Prices we recorded when we last checked each store for this exact variant.

XPERT Moto Gear$403.95CheapestIn stockMotoHeaven$410.99In stock
5 stores at this price$431.99
Adventure On StoreIn stockCoffs MotorsportsIn stockGold Coast Dirt Bike PerformanceIn stockShark LeathersIn stockV-Twins MotorcyclesIn stock

Product details

The K&N RK-3942 High-Flow Air Intake System increases engine intake airflow and delivers more horsepower & torque to your Harley-Davidson® motorcycle. The intake system increases power by eliminating the stock OE air cleaner and replacing it with a complete High-Flow Air Intake System. The sturdy, custom aluminium backing plate mounts directly to the throttle body via an aluminium integrated, internal-run breather system. The intake system comes with a K&N Air Filter for high airflow and long service intervals. The K&N High-Flow Air Filter is washable, reusable, pre-oiled and ready for installation.

Features:

  • Designed for Harley-Davidson motorcycles.
  • Increase horsepower and torque.
  • Easy to install.
  • Made in the USA.

Specifications:

  • Estima ted Horsepower Gain: 9.32 HP @ 4803 RPM
  • Replacement Filter: E-3980
  • Air Filter Material: Cotton Gauze
  • Air Filter Height: 56mm
  • Inlet Diameter: 33mm
  • Overall Height: 56mm

Price history

Recorded changes for this exact variant.

Step chart of dated store-price observations. Solid lines show confirmed crawl coverage, dashed lines show overdue missed-check spans, and every line stops at the last confirmed price.

  1. 1XPERT Moto Gear9 points · last checked 22 Aug 2026
  2. 2MotoHeaven7 points · last checked 21 Aug 2026
  3. 3Adventure On Store1 point · last checked 22 Aug 2026
  4. 4Coffs Motorsports1 point · last checked 22 Aug 2026
  5. 5Gold Coast Dirt Bike Performance3 points · last checked 22 Aug 2026
  6. 6Shark Leathers1 point · last checked 22 Aug 2026

1 more store series is not shown to keep the chart readable.

Solid steps show periods confirmed by the store’s change-only price history and completed crawl record: if the price had changed at a check, another point would appear. Dashed steps show overdue periods with no completed crawl confirmation. Every line stops at that listing’s last confirmed check and is never extended to today. Prices are not live and may have changed since the last point shown.

How we collect and compare prices
Cheapest we found: $403.95 · XPERT Moto GearJump to comparison