Skip to product information
1 of 7

K&N Engineering K&N Red Intake System for Harley Davidson RK-3909-1

K&N Engineering K&N Red Intake System for Harley Davidson RK-3909-1

Regular price $314.99
Regular price Sale price $314.99
Sale Sold out

Shipping calculated at checkout.

Low stock: 2 left

Emissions

✅ CARB Approved
CARB EO #D-269-35/55
Quantity

Shipping & returns

Shipping details

In-stock orders are processed within 48 hours; transit time is additional.

International orders include export processing and customs clearance. Duties, taxes and brokerage are extra; final freight charges may change after remeasurement.

Read the shipping policy

Returns

Need help with a return? Request authorization within 30 days of delivery for eligible unused, uninstalled items. See details for exclusions and applicable fees.

Read the full return policy
Return details & how to start

Request return authorization (RMA) within 30 days of delivery for eligible items. Keep items unused and uninstalled, with original packaging and accessories. Electronics, liquids, special orders and other categories are excluded.

Email sales@frsport.com with RETURN and your order number in the subject to request an RMA. Please wait for return authorization before sending your item back.

Wrong part/size or change of mind: a 20% return processing fee applies, plus applicable shipping costs.

Original shipping is non-refundable. For orders shipped free, the actual outbound shipping cost is deducted from the refund. Return shipping is prepaid by the customer.

After payment capture, cancellations and refunds generally incur a 5% processing fee, except for our error, confirmed defects or confirmed carrier loss. The 5% and 20% fees do not stack; only the greater applicable fee applies. Store credit waives the 5% fee, but applicable return fees remain.

Missing, incorrect or transit-damaged items: report within 3 business days of receipt with photos of the product and packaging.

For defective items, contact us for help with the manufacturer's warranty process. The manufacturer decides the claim.

KN Motorcycle Air Intake Systems- Harley Davidson

Air Cleaner Assembly

K&N's RK Series was developed to get more horsepower from your Twin Cam Harley-Davidson engine. Built around the legendary K&N High-Flow Air Filter, the this RK Series assembly includes an innovative powder coated billet aluminum backplate 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. This RK Series assembly retains a factory appearance by utilizing the stock air cleaner cover. The RK-3910-1 comes with a larger air filter and longer spacers than the RK-3909-1.

The latest addition to K&N's RK Series was developed to get more horsepower from your Twin Cam Harley-Davidson engine. Provides a significant airflow increase to the engine without sacrificing filtration.



Vehicle Fitments:

Year Make Model Submodel
1999 - 2007 Harley Davidson FLHR Road King Base
2007 Harley Davidson FLHRC Road King Classic Base
2002 - 2006 Harley Davidson FLHRCI Road King Classic Base
2003 - 2006 Harley Davidson FLHRI Road King Base
2004 - 2007 Harley Davidson FLHRS Road King Custom Base
2004 - 2006 Harley Davidson FLHRSI Road King Custom Base
1999 - 2007 Harley Davidson FLHT Electra Glide Standard Base
1999 - 2007 Harley Davidson FLHTC Electra Glide Classic Base
2002 - 2006 Harley Davidson FLHTCI Electra Glide Classic Base
2007 Harley Davidson FLHTCU Electra Glide Ultra Classic Base
2002 - 2006 Harley Davidson FLHTCUI Electra Glide Ultra Classic Base
2003 - 2006 Harley Davidson FLHTI Electra Glide Standard Base
2006 - 2007 Harley Davidson FLHX Street Glide Base
2006 Harley Davidson FLHXI Street Glide Base
2006 Harley Davidson FLST Heritage Softail Base
2000 - 2012 Harley Davidson FLSTC Heritage Softail Classic Base
2002 - 2006 Harley Davidson FLSTCI Heritage Softail Classic Base
2000 - 2012 Harley Davidson FLSTF Fat Boy Base
2010 - 2012 Harley Davidson FLSTFB Fat Boy Lo Base
2001 - 2006 Harley Davidson FLSTFI Fat Boy Base
2006 Harley Davidson FLSTI Heritage Softail Base
2005 - 2012 Harley Davidson FLSTN Softail Deluxe Base
2005 - 2006 Harley Davidson FLSTNI Softail Deluxe Base
2000 - 2003 Harley Davidson FLSTS Heritage Springer Base
2005 - 2007 Harley Davidson FLSTSC Softail Springer Classic Base
2005 - 2006 Harley Davidson FLSTSCI Softail Springer Classic Base
2001 - 2003 Harley Davidson FLSTSI Heritage Springer Base
1999 - 2007 Harley Davidson FLTR Road Glide Base
2002 - 2006 Harley Davidson FLTRI Road Glide Base
2010 - 2011 Harley Davidson FLTRX Road Glide Custom Base
2008 - 2009 Harley Davidson FXCW Rocker Base
2008 - 2011 Harley Davidson FXCWC Rocker C Base
1999 - 2007 Harley Davidson FXD Dyna Super Glide Base
2007 Harley Davidson FXDB Street Bob Base
2006 Harley Davidson FXDBI Street Bob Base
2005 - 2007 Harley Davidson FXDC Super Glide Custom Base
2005 - 2006 Harley Davidson FXDCI Super Glide Custom Base
2004 - 2006 Harley Davidson FXDI Dyna Super Glide Base
2006 Harley Davidson FXDI35 Dyna 35th Anniversary Super Glide Base
1999 - 2007 Harley Davidson FXDL Dyna Low Rider Base
2004 - 2006 Harley Davidson FXDLI Dyna Low Rider Base
1999 - 2000 Harley Davidson FXDS-Conv Dyna Convertible Base
1999 - 2007 Harley Davidson FXDWG Dyna Wide Glide Base
2004 - 2006 Harley Davidson FXDWGI Dyna Wide Glide Base
1999 - 2004 Harley Davidson FXDX Dyna Super Glide Sport Base
2004 - 2005 Harley Davidson FXDXI Dyna Super Glide Sport Base
2001 - 2003 Harley Davidson FXDXT Dyna Super Glide T-Sport Base
2000 - 2007 Harley Davidson FXST Softail Standard Base
2000 - 2009 Harley Davidson FXSTB Night Train Base
2001 - 2006 Harley Davidson FXSTBI Night Train Base
2007 - 2010 Harley Davidson FXSTC Softail Custom Base
2000 - 2007 Harley Davidson FXSTD Softail Deuce Base
2001 - 2006 Harley Davidson FXSTDI Softail Deuce Base
2001 - 2006 Harley Davidson FXSTI Softail Standard Base
2000 - 2006 Harley Davidson FXSTS Springer Softail Base
2001 - 2006 Harley Davidson FXSTSI Springer Softail Base
View full details

Vehicle fitment