A Comprehensive Guide to the Differences between Stage 1-4 Kits

Feb. 24 2023 News By Laconia Harley-Davidson

Harley-Davidson motorcycles are iconic for their distinctive sound and powerful performance. One way to enhance the performance of your Harley-Davidson is by installing a stage kit. Stage kits are a set of performance upgrades that increase horsepower, torque, and overall engine performance.

Harley-Davidson offers four different stages of performance upgrades, from Stage 1 to Stage 4. Each stage kit offers different levels of performance enhancements and can be tailored to suit different types of riding styles and preferences. In this blog post, we'll take a closer look at the differences between each stage kit and what you can expect from each upgrade.

Stage 1 Kit

The Stage 1 kit is the most basic performance upgrade offered by Harley-Davidson. It includes a high-flow air filter and a new exhaust system. This upgrade is designed to increase airflow to the engine, allowing it to breathe more freely and produce more power. The Stage 1 kit can increase horsepower by up to 10%, and it also produces a deeper, more aggressive exhaust note.

Stage 2 Kit

The Stage 2 kit builds on the upgrades included in the Stage 1 kit. It includes a high-performance camshaft and a set of adjustable pushrods. These upgrades help to increase low-end torque and overall power output. The Stage 2 kit can increase horsepower by up to 20%, and it's ideal for riders who want more power for acceleration and passing.

Stage 3 Kit

The Stage 3 kit is a more extensive upgrade that includes larger diameter cylinders, high compression forged aluminum pistons and a performance cam upgrade. This upgrade is designed to increase the engine's overall capacity, allowing it to produce even more power and torque. The Stage 3 kit can increase horsepower by up to 30%, and it's best suited for riders who want maximum power for high-speed cruising and long-distance touring.

Stage 4 Kit

The Stage 4 kit is the most comprehensive upgrade offered by Harley-Davidson. It includes all of the upgrades included in the previous stages, as well as additional enhancements such as a high-performance clutch, upgraded fuel injectors, and a high-capacity oil pump. The Stage 4 kit is designed for the most demanding riders who want maximum power and performance. This upgrade can increase horsepower by up to 40%, and it's ideal for riders who want the ultimate in speed and acceleration.


It's important to note that each stage kit is designed to work together as a complete system. If you're considering a performance upgrade for your Harley-Davidson, it's essential to choose the stage kit that's right for your riding style and preferences. Working with a qualified Harley-Davidson dealer or technician can help ensure that your bike is properly upgraded and tuned for maximum performance.


In conclusion, Harley-Davidson stage kits offer a range of performance upgrades that can enhance the power and performance of your motorcycle. From the basic Stage 1 kit to the comprehensive Stage 4 kit, each upgrade offers different levels of power and performance enhancements. Choosing the right stage kit for your riding style and preferences can help you get the most out of your Harley-Davidson and take your riding experience to the next level.