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The K&N RK-3942 High-Flow Air Intake System increases engine intake airflow and delivering 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 aluminum backing plate mounts directly to the throttle body via an aluminum integrated, internal-run breather system. The intake system comes with a K&N Air Filter for high air flow and long service intervals. The K&N High-Flow Air Filter is washable, reusable, pre-oiled and ready for installation.

Designed for Harley-Davidson motorcycles
Increase horsepower and torque
Easy to install
Made in USA
Backed by K&N warranty

For over 40 years K&N has been designing and manufacturing performance air filters for the motorcycle and ATV enthusiast interested in maximizing horsepower and acceleration. Our air filter is designed to achieve high, virtually unrestricted air flow while maintaining filtration levels critical to ensure long engine life. K&N Air Filters will NOT void Motorcycle Warranty and are environmentally friendly. K&N Reusable Air Filters reduce the volume of disposable air filters that end up in landfills!

  • Designed to provide increased Horsepower and Acceleration
  • Pleated cotton media provides a large filtration area offering low restriction and long service intervals
  • Multi-Layers of woven cotton gauze media offers excellent filtration
  • Fits directly into OEM Airbox with application specific Sealing Bead ensuring a precise fit
  • No fuel Management modifications are normally required to obtain increased performance
  • Washable & reusable, most are pre-oiled and ready to ride!

2012 Harley Davidson FLSTFB Softail Fat Boy LO
2013 Harley Davidson FLD Dyna Switchback
2013 Harley Davidson FLHRC Road King Classic
2013 Harley Davidson FLHTCKSE 1803 CVO Ultra LTD
2013 Harley Davidson FLHTCU 1690 Ultra Classic Electra Glide LTD
2013 Harley Davidson FLHTK Electra Glide Ultra Limited
2013 Harley Davidson FLHX Street Glide
2013 Harley Davidson FLHXSE 1803 CVO Street Glide
2013 Harley Davidson FLSTC Softail Heritage Classic
2013 Harley Davidson FLSTF Softail Fat Boy
2013 Harley Davidson FLSTFB Softail Fat Boy LO
2013 Harley Davidson FLSTN Softail Deluxe
2013 Harley Davidson FLTR 1803 CVO Road Glide Custom
2013 Harley Davidson FXDC Dyna Super Glide Custom
2013 Harley Davidson FXDF Dyna Fat Bob
2013 Harley Davidson FXDWG Dyna Wide Glide
2013 Harley Davidson FXSB Breakout
2013 Harley Davidson FXSBSE 1803 Breakout CVO
2013 Harley Davidson FXSBSE 1803 CVO Softail
2013 Harley Davidson FXST Softail Standard
2014 Harley Davidson FLD Dyna Switchback
2014 Harley Davidson FLHRC Road King Classic
2014 Harley Davidson FLHTCU 1690 Ultra Classic Electra Glide LTD
2014 Harley Davidson FLHTCUTG 1803 Tri Glide Trike
2014 Harley Davidson FLHTK Electra Glide Ultra Limited
2014 Harley Davidson FLHTKSE 1803 Ultra Limited
2014 Harley Davidson FLHXSE 1803 CVO Street Glide
2014 Harley Davidson FLSTC Softail Heritage Classic
2014 Harley Davidson FLSTF Softail Fat Boy
2014 Harley Davidson FLSTFB Softail Fat Boy LO
2014 Harley Davidson FLSTN Softail Deluxe
2014 Harley Davidson FXDC Dyna Super Glide Custom
2014 Harley Davidson FXDF Dyna Fat Bob
2014 Harley Davidson FXDWG Dyna Wide Glide
2014 Harley Davidson FXSB Breakout
2014 Harley Davidson FXSBSE 1803 Breakout CVO
2014 Harley Davidson FXSBSE 1803 CVO Softail Deluxe
2014 Harley Davidson FXST Softail Standard
2015 Harley Davidson FLD Dyna Switchback
2015 Harley Davidson FLHRC Road King Classic
2015 Harley Davidson FLHTCU 1690 Ultra Classic Electra Glide LTD
2015 Harley Davidson FLHTCUTG Tri Glide Ultra Trike
2015 Harley Davidson FLHTKSE 1803 Ultra Limited
2015 Harley Davidson FLHXS Street Glide Special
2015 Harley Davidson FLHXSE 1803 CVO Street Glide
2015 Harley Davidson FLHXSE CVO Street Glide
2015 Harley Davidson FLHXSE Street Glide Special
2015 Harley Davidson FLS Softail Slim
2015 Harley Davidson FLSTC Softail Heritage Classic
2015 Harley Davidson FLSTF Softail Fat Boy
2015 Harley Davidson FLSTFB Softail Fat Boy LO
2015 Harley Davidson FLSTN Softail Deluxe
2015 Harley Davidson FLTRUSE CVO Road Glide Ultra
2015 Harley Davidson FLTRXS Road Glide Special
2015 Harley Davidson FXDC Dyna Super Glide Custom
2015 Harley Davidson FXDF Dyna Fat Bob
2015 Harley Davidson FXDWG Dyna Wide Glide
2015 Harley Davidson FXSB Breakout
2015 Harley Davidson FXSBSE 1803 CVO Softail Deluxe
2015 Harley Davidson FXST Softail Standard
2016 Harley Davidson FLD Dyna Switchback
2016 Harley Davidson FLHXS Street Glide Special
2016 Harley Davidson FLHXSE 1803 CVO Street Glide
2016 Harley Davidson FLHXSE Street Glide Special
2016 Harley Davidson FLS Softail Slim
2016 Harley Davidson FLSTC Softail Heritage Classic
2016 Harley Davidson FLSTF Softail Fat Boy
2016 Harley Davidson FLSTFB Softail Fat Boy LO
2016 Harley Davidson FLSTN Softail Deluxe
2016 Harley Davidson FLTRUSE CVO Road Glide Ultra
2016 Harley Davidson FLTRXS Road Glide Special
2016 Harley Davidson FXDF Dyna Fat Bob
2016 Harley Davidson FXDWG Dyna Wide Glide
2016 Harley Davidson FXSB Breakout
2017 Harley Davidson FLD Dyna Switchback
2017 Harley Davidson FLHXS Street Glide Special
2017 Harley Davidson FLHXSE 1803 CVO Street Glide
2017 Harley Davidson FLS Softail Slim
2017 Harley Davidson FLSTC Softail Heritage Classic
2017 Harley Davidson FLSTF Softail Fat Boy
2017 Harley Davidson FLSTFB Softail Fat Boy LO
2017 Harley Davidson FLSTN Softail Deluxe
2017 Harley Davidson FLTRUSE CVO Road Glide Ultra
2017 Harley Davidson FLTRXS Road Glide Special
2017 Harley Davidson FXDF Dyna Fat Bob
2017 Harley Davidson FXDWG Dyna Wide Glide
2017 Harley Davidson FXSB Breakout
2018 Harley Davidson FLFBS Softail Fat Boy
2018 Harley Davidson FLHXS Street Glide Special
2018 Harley Davidson FLHXSE 1803 CVO Street Glide
2018 Harley Davidson FLSL Softail Slim
2018 Harley Davidson FLSTC Softail Heritage Classic
2018 Harley Davidson FLTRXS Road Glide Special
2018 Harley Davidson FXBR Breakout
2019 Harley Davidson FLFBS Softail Fat Boy
2019 Harley Davidson FLHXS Street Glide Special
2019 Harley Davidson FLHXSE 1803 CVO Street Glide
2019 Harley Davidson FLSL Softail Slim
2019 Harley Davidson FLSTC Softail Heritage Classic
2019 Harley Davidson FLTRXS Road Glide Special
2019 Harley Davidson FXBR Breakout
2020 Harley Davidson FLFBS Softail Fat Boy
2020 Harley Davidson FLHXS Street Glide Special
2020 Harley Davidson FLHXSE 1803 CVO Street Glide
2020 Harley Davidson FLSL Softail Slim
2020 Harley Davidson FLSTC Softail Heritage Classic
2020 Harley Davidson FLTRXS Road Glide Special
2020 Harley Davidson FXBR Breakout
2021 Harley Davidson FLFBS Softail Fat Boy
2021 Harley Davidson FLHXS Street Glide Special
2021 Harley Davidson FLHXSE 1803 CVO Street Glide
2021 Harley Davidson FLSL Softail Slim
2021 Harley Davidson FLSTC Softail Heritage Classic
2021 Harley Davidson FLTRXS Road Glide Special
2021 Harley Davidson FXBR Breakout

K&N AIR FILTER KRK-3942

by K&N
SKU: KNRK3942
Regular price $431.99 $410.00 Save 5%
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The K&N RK-3942 High-Flow Air Intake System increases engine intake airflow and delivering 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 aluminum backing plate mounts directly to the throttle body via an aluminum integrated, internal-run breather system. The intake system comes with a K&N Air Filter for high air flow and long service intervals. The K&N High-Flow Air Filter is washable, reusable, pre-oiled and ready for installation.

Designed for Harley-Davidson motorcycles
Increase horsepower and torque
Easy to install
Made in USA
Backed by K&N warranty

For over 40 years K&N has been designing and manufacturing performance air filters for the motorcycle and ATV enthusiast interested in maximizing horsepower and acceleration. Our air filter is designed to achieve high, virtually unrestricted air flow while maintaining filtration levels critical to ensure long engine life. K&N Air Filters will NOT void Motorcycle Warranty and are environmentally friendly. K&N Reusable Air Filters reduce the volume of disposable air filters that end up in landfills!

  • Designed to provide increased Horsepower and Acceleration
  • Pleated cotton media provides a large filtration area offering low restriction and long service intervals
  • Multi-Layers of woven cotton gauze media offers excellent filtration
  • Fits directly into OEM Airbox with application specific Sealing Bead ensuring a precise fit
  • No fuel Management modifications are normally required to obtain increased performance
  • Washable & reusable, most are pre-oiled and ready to ride!

2012 Harley Davidson FLSTFB Softail Fat Boy LO
2013 Harley Davidson FLD Dyna Switchback
2013 Harley Davidson FLHRC Road King Classic
2013 Harley Davidson FLHTCKSE 1803 CVO Ultra LTD
2013 Harley Davidson FLHTCU 1690 Ultra Classic Electra Glide LTD
2013 Harley Davidson FLHTK Electra Glide Ultra Limited
2013 Harley Davidson FLHX Street Glide
2013 Harley Davidson FLHXSE 1803 CVO Street Glide
2013 Harley Davidson FLSTC Softail Heritage Classic
2013 Harley Davidson FLSTF Softail Fat Boy
2013 Harley Davidson FLSTFB Softail Fat Boy LO
2013 Harley Davidson FLSTN Softail Deluxe
2013 Harley Davidson FLTR 1803 CVO Road Glide Custom
2013 Harley Davidson FXDC Dyna Super Glide Custom
2013 Harley Davidson FXDF Dyna Fat Bob
2013 Harley Davidson FXDWG Dyna Wide Glide
2013 Harley Davidson FXSB Breakout
2013 Harley Davidson FXSBSE 1803 Breakout CVO
2013 Harley Davidson FXSBSE 1803 CVO Softail
2013 Harley Davidson FXST Softail Standard
2014 Harley Davidson FLD Dyna Switchback
2014 Harley Davidson FLHRC Road King Classic
2014 Harley Davidson FLHTCU 1690 Ultra Classic Electra Glide LTD
2014 Harley Davidson FLHTCUTG 1803 Tri Glide Trike
2014 Harley Davidson FLHTK Electra Glide Ultra Limited
2014 Harley Davidson FLHTKSE 1803 Ultra Limited
2014 Harley Davidson FLHXSE 1803 CVO Street Glide
2014 Harley Davidson FLSTC Softail Heritage Classic
2014 Harley Davidson FLSTF Softail Fat Boy
2014 Harley Davidson FLSTFB Softail Fat Boy LO
2014 Harley Davidson FLSTN Softail Deluxe
2014 Harley Davidson FXDC Dyna Super Glide Custom
2014 Harley Davidson FXDF Dyna Fat Bob
2014 Harley Davidson FXDWG Dyna Wide Glide
2014 Harley Davidson FXSB Breakout
2014 Harley Davidson FXSBSE 1803 Breakout CVO
2014 Harley Davidson FXSBSE 1803 CVO Softail Deluxe
2014 Harley Davidson FXST Softail Standard
2015 Harley Davidson FLD Dyna Switchback
2015 Harley Davidson FLHRC Road King Classic
2015 Harley Davidson FLHTCU 1690 Ultra Classic Electra Glide LTD
2015 Harley Davidson FLHTCUTG Tri Glide Ultra Trike
2015 Harley Davidson FLHTKSE 1803 Ultra Limited
2015 Harley Davidson FLHXS Street Glide Special
2015 Harley Davidson FLHXSE 1803 CVO Street Glide
2015 Harley Davidson FLHXSE CVO Street Glide
2015 Harley Davidson FLHXSE Street Glide Special
2015 Harley Davidson FLS Softail Slim
2015 Harley Davidson FLSTC Softail Heritage Classic
2015 Harley Davidson FLSTF Softail Fat Boy
2015 Harley Davidson FLSTFB Softail Fat Boy LO
2015 Harley Davidson FLSTN Softail Deluxe
2015 Harley Davidson FLTRUSE CVO Road Glide Ultra
2015 Harley Davidson FLTRXS Road Glide Special
2015 Harley Davidson FXDC Dyna Super Glide Custom
2015 Harley Davidson FXDF Dyna Fat Bob
2015 Harley Davidson FXDWG Dyna Wide Glide
2015 Harley Davidson FXSB Breakout
2015 Harley Davidson FXSBSE 1803 CVO Softail Deluxe
2015 Harley Davidson FXST Softail Standard
2016 Harley Davidson FLD Dyna Switchback
2016 Harley Davidson FLHXS Street Glide Special
2016 Harley Davidson FLHXSE 1803 CVO Street Glide
2016 Harley Davidson FLHXSE Street Glide Special
2016 Harley Davidson FLS Softail Slim
2016 Harley Davidson FLSTC Softail Heritage Classic
2016 Harley Davidson FLSTF Softail Fat Boy
2016 Harley Davidson FLSTFB Softail Fat Boy LO
2016 Harley Davidson FLSTN Softail Deluxe
2016 Harley Davidson FLTRUSE CVO Road Glide Ultra
2016 Harley Davidson FLTRXS Road Glide Special
2016 Harley Davidson FXDF Dyna Fat Bob
2016 Harley Davidson FXDWG Dyna Wide Glide
2016 Harley Davidson FXSB Breakout
2017 Harley Davidson FLD Dyna Switchback
2017 Harley Davidson FLHXS Street Glide Special
2017 Harley Davidson FLHXSE 1803 CVO Street Glide
2017 Harley Davidson FLS Softail Slim
2017 Harley Davidson FLSTC Softail Heritage Classic
2017 Harley Davidson FLSTF Softail Fat Boy
2017 Harley Davidson FLSTFB Softail Fat Boy LO
2017 Harley Davidson FLSTN Softail Deluxe
2017 Harley Davidson FLTRUSE CVO Road Glide Ultra
2017 Harley Davidson FLTRXS Road Glide Special
2017 Harley Davidson FXDF Dyna Fat Bob
2017 Harley Davidson FXDWG Dyna Wide Glide
2017 Harley Davidson FXSB Breakout
2018 Harley Davidson FLFBS Softail Fat Boy
2018 Harley Davidson FLHXS Street Glide Special
2018 Harley Davidson FLHXSE 1803 CVO Street Glide
2018 Harley Davidson FLSL Softail Slim
2018 Harley Davidson FLSTC Softail Heritage Classic
2018 Harley Davidson FLTRXS Road Glide Special
2018 Harley Davidson FXBR Breakout
2019 Harley Davidson FLFBS Softail Fat Boy
2019 Harley Davidson FLHXS Street Glide Special
2019 Harley Davidson FLHXSE 1803 CVO Street Glide
2019 Harley Davidson FLSL Softail Slim
2019 Harley Davidson FLSTC Softail Heritage Classic
2019 Harley Davidson FLTRXS Road Glide Special
2019 Harley Davidson FXBR Breakout
2020 Harley Davidson FLFBS Softail Fat Boy
2020 Harley Davidson FLHXS Street Glide Special
2020 Harley Davidson FLHXSE 1803 CVO Street Glide
2020 Harley Davidson FLSL Softail Slim
2020 Harley Davidson FLSTC Softail Heritage Classic
2020 Harley Davidson FLTRXS Road Glide Special
2020 Harley Davidson FXBR Breakout
2021 Harley Davidson FLFBS Softail Fat Boy
2021 Harley Davidson FLHXS Street Glide Special
2021 Harley Davidson FLHXSE 1803 CVO Street Glide
2021 Harley Davidson FLSL Softail Slim
2021 Harley Davidson FLSTC Softail Heritage Classic
2021 Harley Davidson FLTRXS Road Glide Special
2021 Harley Davidson FXBR Breakout