Harley Stage Kits (a.k.a. Screamin’ Eagle Upgrade kits) are complete packages of OEM performance parts.
- Stage 1: Intake, exhaust, and ECM remapping
- Stage 2: Cam upgrade with adjustable pushrods
- Stage 3: Big bore cylinders, matching pistons, and cam upgrade
- Stage 4: Stage 3 + Upgraded heads, clutch components, throttle body, and lifters
If you want to find out more about Harley Upgrade kits, this post is for you.
We at PowerSportsGuide have compiled all you need to know under one roof!
What are Harley Stage 1-4 Upgrade Kits?
Powersport vehicle riders love increasing the power of their machines with performance modifications, and Harley owners are no exception.
Many of them use aftermarket parts for the mods, which unfortunately void the warranty in many cases.
Harley understands the needs of its customers and has released a wide range of OEM performance parts under the brand name Screamin’ Eagle.
What’s more, just like many other manufacturers, Harley-Davidson also offers complete Stage (1-4) upgrade kits for their bikes. Each stage represents a different package of upgrades that fit as a set.
The official name of these kits is Screamin’ Eagle Stage Kits, but they are often referred to as Harley Stage Kits, Harley Upgrade Kits, or Harley Performance Kits.
The key advantage of these kits is that they offer great HP and torque improvements without compromising the bike’s warranty coverage.
Are you wondering which parts are involved in each stage, and how much power they add to a Harley?
Let’s get down to the nitty-gritty and talk about these kits in detail!
Harley Stage 1 Kit
What is a Stage 1 Harley Upgrade?
Stage 1 is the entry-level upgrade kit for Harley-Davidson motorcycles, which is intended to increase engine power. As a side effect, it enhances the sound and the look of the bike as well.
This kit is widely popular among riders since its installation doesn’t require disassembling the engine.
Many performance-minded riders claim that Stage 1 is a must-have for any Harley-Davidson since their engines are detuned from the factory.
Harley’s Stage 1 kit is also considered the foundation for 2, 3, and 4 stage kits.
What is included in a Harley Stage 1 kit?
The Harley Stage 1 kit contains four mods including an upgraded Screamin’ Eagle air filter, exhaust pipe, an ECM tuner, and a carburetor rejetting (if required).
The increased airflow and modified fuel metering system produce a noticeable increase in performance and a deeper exhaust sound.
How much power does Stage 1 add to a Harley?
As a rule of thumb, the Stage 1 kit increases a Harley motorcycle’s performance anywhere from 5-10% depending on the model.
How much is a Harley Stage 1 kit?
The Harley Stage 1 kit will cost you from $1,000-$1,500 depending on the type of the engine and the specific intake and exhaust you choose. Note that this price doesn’t include the labor if you don’t install the kit yourself.
Since Stage 1 only involves “bolt-on” performance parts, it can be easily installed even at home with some basic tools.
Harley Stage 2 Kit
What is a Stage 2 Harley upgrade?
Stage 2 is the second-level upgrade kit for Harley-Davidson motorcycles, which offers an instant power increase. It’s recommended for performance-minded riders who are looking for more performance and higher speeds.
Note that installing the Stage 2 kit requires already having Stage 1 installed on the bike.
What is included in a Harley Stage 2 kit?
Simply put, Harley’s Stage 2 kit contains a Screamin’ Eagle performance cam and adjustable pushrods.
These performance parts are intended to increase the duration of the valve opening and lift in the valve train. In other words, the new cam pushes the valves open further and keeps them open longer.
How much power does Stage 2 add to a Harley?
Based on your riding style, you can choose either Torque or Power Stage 2 kits.
The general rule is that the Torque Stage 2 kit increases the performance in the low and mid-RPM range up to 15%.
This translates into a crisp throttle response and faster acceleration at lower speeds, which comes in handy when you pass slower vehicles without shifting down.
In contrast, the Power Stage 2 kit is tuned for the maximum peak power, ensuring a performance increase of up to 25% in the range of mid and upper RPM.
This cam configuration allows you to ride at thrilling top speeds while pushing the tachometer towards the red line!
How much is a Harley Stage 2 kit?
Compared to its brothers, the Harley Stage 2 kit is fairly affordable since it costs only $450-$550. This is no surprise since this kit only contains an upgraded cam and adjustable pushrods.
Don’t forget that you need to already have the Stage 1 kit installed before installing Stage 2.
Harley Stage 3 Kit
What is a Harley Stage 3 upgrade?
As they say, “there’s no replacement for displacement,” which is why the Stage 3 kit is widely popular. It contains a big bore cylinder kit with a cam upgrade!
This kit is ideal for owners who want to expand their displacements but don’t want to invest in a complete aftermarket engine.
What is included in a Harley Stage 3 kit?
The Harley Stage 3 kit contains many key performance parts, including:
- Big bore cylinders
- Matching pistons and rings
- High-performance valve springs
- High capacity lifters
- Upgraded cam
- Cam bearing
- Clutch springs
- Top end gaskets
Since the Stage 3 kit comes with bolt-on cylinders, the entire kit can be installed without pulling out the engine from the frame.
How much power does Stage 3 add to a Harley?
Stage 3 can increase the bike’s performance by anywhere from 15-39% in the mid and upper RPM range. However, it strongly depends on the size and features of the base engine.
Examples:
- Stage III Kit 107CI to 114CI – Power increase: up to 39%
- Stage III Kit 114CI to 117CI – Power increase: up to 24%
- Stage III Kit 107CI to 119CI – Power increase: up to 23% (and 17% more torque)
- Stage III Kit 114CI to 122CI – Power increase: up to 15% (and 13% more torque)
How much is a Harley Stage 3 kit?
The price of a Harley Stage 3 kit averages between $1,700 and $1,900 without labor costs.
Harley Stage 4 Kit
What is a Harley Stage 4 upgrade?
The Harley Stage 4 upgrade kit is basically a Stage 3 kit extended with upgraded heads and a throttle body. This package is the highest level performance package from Harley right now.
If you are looking for maximum performance but want to keep the warranty on your bike, you can’t go wrong with a Stage 4 kit!
What is included in a Harley Stage 4 kit?
The Harley Stage 4 kit contains many key performance parts, including:
- Big bore cylinders
- Matching pistons and rings
- High-performance valve springs
- High capacity lifters
- Upgraded cam
- Cam bearing
- Clutch springs
- Top end gaskets
- Upgraded heads
- Improved throttle body
How much power does Stage 4 add to a Harley?
Depending on the base engine, the Harley Stage 4 kit can boost engine power up anywhere from 40% – 50+%.
Some examples:
- Stage IV Kit 107CI to 114CI – Power increase: up to 52%
- Stage IV Kit 114 to 117CI – Power increase: up to 40%
How Much is a Harley Stage 4 kit?
The prices of Harley Stage 4 kits range from $2,200 up to a whopping $3,800 without labor costs.
Takeaways – FAQs About Screamin’ Eagle Kits
As a takeaway, we’ve answered the most frequent questions on the topic.
What is the Screamin’ Eagle package?
Screamin’ Eagle packages are the OEM Stage performance kits manufactured and marketed by Harley-Davidson. Installing these packages gives your bike a significant HP and toque increase without voiding the warranty.
What are the 4 Stages for Harley-Davidson?
- Stage 1: Intake, exhaust, and ECM remapping
- Stage 2: Cam upgrade with adjustable pushrods
- Stage 3: Big bore cylinders, matching pistons, and cam upgrade
- Stage 4: Stage 3 + Upgraded heads, clutch components, throttle body, and lifters
How much is a Screamin’ Eagle upgrade?
The prices of Screamin’ Eagle kits start at $450 and go up to the whopping $3,800:
- Stage 1: $1,000-$1,500
- Stage 2: $450-$550
- Stage 3: $1,700-$1,900
- Stage 4: $2,200-$3,800
Although Stage 2 is only about $500 it only packs an advanced cam and pushrods, which can be added after you have installed Stage 1.
Therefore, you can install Stage 1 separately, or Stage 1 + Stage 2 together if you are looking for more power.
Is Screamin’ Eagle made by Harley?
Yes, Screamin’ Eagle Performance Stage Kits are manufactured by Harley-Davidson!
References:
https://haleshd.com/news-article/32558/harley-davidson-motorcycle-stage-kits
https://www.harley-davidson.com/
