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FAQ: How to Stage 1 Kit a Harley-Davidson Sportster

Stage 1 KitSo you want to get a little more power from your Harley-Davidson Sportster, but you’re not sure where to start. You’ve come to the right place. Here’s some basic info on Stage 1 tuning your Harley-Davidson Sportster, the pros and cons, and the costs. We’ll look at what it means to Stage 1 a motorcycle, what the required components are, how to do it, and what benefits you can expect.

What is the Stage 1 Kit and where can I find / buy it?
Stage 1 upgrades aren’t a “kit” per say, they’re a combination of enhancements or add-ons to your motorcycle to designed to improve performance. You can buy parts individually and adopt different strategies based on your preferences or budget.

The key components of a Stage 1 kit are:

  • Free breathing air filter
  • Free breathing exhaust
  • Rejetted carburetor (for 1957 to 2006 Sportster models) or remapped EFI (for 2007+ Sportster models with fuel injection)

Sportster Profile

What does free breathing mean and what is the Harley Tax?


Free breathing is a state of being nonrestricted. In North America and Europe, the automotive industries face heavy regulation for environmental concerns. Motorcycles often come restricted so as to meet emission tests and other standards of compliance. Restrictions can be found in motorcycle air intakes, throttles, variators, exhausts, carburetor jetting, fuel-injection mapping, and more. The “Harley Tax” is the cost that many choose to pay to get their Sportsters or other Harleys running as they should’ve come from the factory, were it not from the government trying to save us from ourselves.

Depending on your local laws, Stage 1 upgrades may or may not be legal. They may leave your bike no longer meeting emission, noise, or other standards. They may also increase your fuel consumptionand if done wrong could harm your engine.

If you understand the risks and want to find out more about Stage 1, the best and easiest bang-for-your-buck way of improving your Harley-Davidson Sportster or any other motorcycle’s performance. Click Next!


Here’s a quick look at some of the things you’ll need for a Stage 1 upgrade and why you’ll need them. We recommend you do the upgrades in this order and preferably all at once for the best interests of your engine and your wallet. This is Page 2 of our Stage 1 Kit guide, if you’ve missed Page 1 we recommend you check it out.

Air Cleaners
There are a variety of hyperchargers and air cleaners available for the Sportster and for other motorcycles. My 2007 Harley-Davidson Sportster XL-883 has a Screamin’ Eagle Air Cleaner on it. This cleaner has a surface area of roughly double the stock cleaner from the factory. Imagine you had double the lung capacity next time you had to run around the block. Expect to pay around $60 and up depending on features and design. For bang-for-buck-air-suck we recommend the Screamin’ Eagle filter.


Free Breathing Exhaust
Opening up the exhaust can range from slip-on mufflers to full exhaust systems. The costs range from a couple hundred to near thousands. Slip-ons are easy to install, resemble stock, and help with performance. Full exhaust systems may increase performance further or look much more appealing, but come at a much higher price range. We use the Screamin’ Eagle II exhaust slip-on.

Harley-Davidson instructions clearly state: changes to both air cleaners and exhaust systems will require ECM recalibration. We recommend swapping air cleaners and exhausts at the same time, so as to avoid paying for recalibration twice.

Sportster Screaming Eagle Air Cleaner

Rejetted Carburetor / Remapped EFI
When you start touching your motorcycle’s air intake and exhaust you need to make sure that you’ve adjusted your bike to run a proper fuel mixture to compensate. If you have a carburetted Sportster (1957 – 2006 models) you’ll need to look at changing your carburettor jetting. For 2007 and newer Sportster models you’ll need to re-map the EFI. This can be achieved with use of tools such as a Power Commander.

Expected Power Gains
Expect to gain about a 10% increase in power by paying “The Harley Tax” or Stage 1 kitting your motorcycle. After a successful Stage 1, 883cc Sportsters should begin seeing horsepower in the low to mid 50s, and torque numbers at about the 50 ft-lbs mark. 

Soon we’ll have a step by step instruction on how to use a Power Commander 3 USB on a Harley-Davidson Sportster. You may also be interested in learning how to identify what type of Sportster you have based on its VIN #. For now please leave a comment letting us know what tunning you’ve done and please ask some questions.

More Harley-Davidson Sportster Resources

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4 comments

  1. I did a full stage 1 on my 2013 superlow . I did rear fender off a 48 shorter rear fender and did the chop 5 inch off my front with a raw steel look on the front with clear coat… I did the superlow because I like to build from the lines of the 883 and make it mine. I also like rimes and big tank . from the back most don’t know what it is now .also 10 inch apes with hide wires in bars. stage 1 did a dk custom high flow k&n filter and two breather bolts . why bolts from dk custom it take the old hot air and old air with oil air out of engine not not back in to the engine to re burn it . not good. you must let out the old air and bring in new… will run better night and day when I give it gas and go. great thing is breather bolts. then I did custom slash part 1801-0478 fire power with mod to baffels made holes and took out the wraping around the baffle. much better flow and sound.. 10 mm wires and screamin eagle plugs down load from Harley eagle tuner.. the dk air intake is better then my eagel I had . much more power and the bolts you get with the kit breather bolts a must. bike is running great and cool engine is happy. next fall the 1250 kit with a cam and coil is the next move with the best $1500.00 2 into one made by sikpipes black with long mid part of pipe after the one to two meets, and 1 3/4 inch wide to 3 inch rear with custom cut at end of pipe. will be bad and mine.. be a safe rider

  2. I did a stage 1 on my 2005 Sport 883 (5000 miles) and could hardly believe the difference, feels more like 15% more go.

What do you think?