The BoosterPlug is accepted world wide, as a brilliant and affordable aftermarket part to transform your Harley Davidson Road King FLHR from ”OK” to ”Absolutely Marvelous”.
No need to spend a small fortune on complicated parts like the Power Commander + endless Dyno hours, to make your bike run like it should have from the factory.
We designed the BoosterPlug to be easy and fast to install, so it comes with the correct connectors to let you install it without cutting and splicing wires. No additional parts required.
A true plug and play aftermarket solution that will make your bike so much better:
- Much better and softer throttle response
- Quicker acceleration
- No more low speed surging
- Stronger and more reliable Idle
- Reduced popping in your aftermarket exhaust
This version of the BoosterPlug covers all versions of the Harley Davidson Road King FLHR with the Milwaukee 8 engine (2017 to 2020).
If you have an older Road King FLHR, you can find the BoosterPlug for it in the related products below.
Please note that we can not build a BoosterPlug for the "2021 and newer" model due to new emission regulations. You can see the detailed explanation here
General Installation Instructions
Bike Specific Installation Instructions