Air and Fuel› Air Cleaners, Filters, Intakes and Components

K&N Engineering

FILTER KIT - HARLEY DAVID

$368.34

SKU: K001 RK-3921

Special Order
Special Order
Ships in 4–6 weeks
Free Shipping
Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Description

K&N's RK Series air intake systems have been developed to get more horsepower from your Harley-Davidson motorcycle. Built around the legendary K&N high-flow air filter, the RK series assembly includes an innovative powder coated, billet aluminum back plate that eliminates external breathers and features a built-in, dyno tuned velocity stack. The result is a significant airflow increase to the engine without sacrificing filtration. The RK series assembly also retains a factory appearance by utilizing the stock air cleaner cover.

Fitment

Fitment Guaranteed

Don’t gamble
on fit.

Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

BrandK&N Engineering
Part NumberK001 RK-3921

Videos

K&N Performance Air Intake System Installation

K&N Performance Air Intake System Installation
Install K&N Aircharger Intake System on Harley Davidson | Law Abiding Biker Podcast

Install K&N Aircharger Intake System on Harley Davidson | Law Abiding Biker Podcast
Install K&N Aircharger Intake - Harley Davidson Street 500

Install K&N Aircharger Intake - Harley Davidson Street 500
Harley Softail, Dyna Wide, Fat Boy, Heritage, Night Train, Rocker [#63-1125] Air Intake Installation

Harley Softail, Dyna Wide, Fat Boy, Heritage, Night Train, Rocker [#63-1125] Air Intake Installation
K&N High Flow Air Charger Intake Kit For Harley Review at RevZilla.com

K&N High Flow Air Charger Intake Kit For Harley Review at RevZilla.com
K&N Air Filter Installation for Harley-Davidson Street 500 & 750

K&N Air Filter Installation for Harley-Davidson Street 500 & 750
Harley Davidson [#63-1125] Air Intake Installation

Harley Davidson [#63-1125] Air Intake Installation
Top 4 Best Air Cleaners for Harley 103 [Review] - Stage 1 Air Cleaner for Harley Davidson [2026]

Top 4 Best Air Cleaners for Harley 103 [Review] - Stage 1 Air Cleaner for Harley Davidson [2026]

Buy with Confidence

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

View Full Return Policy