How To Measure My Harley Slip On Exhaust: A Simple Guide

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So, you’re looking to upgrade your Harley-Davidson’s exhaust with some slip-on pipes? Great choice! It’s a fantastic way to boost performance, improve the sound, and customize the look of your ride. But before you start shopping, you’ll need to know how to measure your existing exhaust to ensure a proper fit.

Don’t worry, it’s not as complicated as it sounds. This guide will walk you through the entire process, step by step, making sure you get the right measurements for your new slip-ons. We’ll cover everything from identifying the components to using the right tools and understanding the terminology. Let’s get started and make sure you get the perfect fit!

This guide is designed for both seasoned mechanics and DIY enthusiasts. We’ll break down each step so that anyone can confidently measure their Harley exhaust. By the end, you’ll be able to accurately determine the size and type of slip-on exhaust you need, saving you time and preventing costly returns.

Table of Contents show

Understanding Harley-Davidson Slip-on Exhausts

Before we dive into the measuring process, let’s clarify what we mean by “slip-on” exhausts. Slip-on exhausts are a popular upgrade for Harley-Davidson motorcycles because they’re relatively easy to install and offer significant improvements in sound, performance, and aesthetics.

Unlike a full exhaust system, which replaces the entire exhaust from the engine to the tailpipe, slip-ons only replace the mufflers. They “slip on” to the existing head pipes, hence the name. This makes them a more cost-effective option than a full system while still providing a noticeable upgrade.

Key Components of a Slip-on Exhaust System

Mufflers: These are the main components you’ll be replacing. They control the sound and backpressure of the exhaust gases.
Head Pipes: These pipes connect to the engine and run to the mufflers. You won’t typically replace these with a slip-on upgrade.
Clamps: These secure the mufflers to the head pipes. They are often included with the new slip-on exhausts.
Mounting Brackets: These brackets help to secure the mufflers to the motorcycle frame.

Why Measuring Is Crucial

Accurate measurements are vital for a few key reasons:

Proper Fit: Ensure the new slip-ons will actually fit your bike’s head pipes.
Performance: The correct size and design contribute to optimal exhaust flow, maximizing performance gains.
Appearance: Get the look you want. Different mufflers have different lengths and diameters.
Avoiding Returns: Accurate measurements prevent the hassle of returning and exchanging incorrect parts.

Tools You’ll Need

Gathering the right tools will make the measuring process much easier and more accurate. Here’s a list of essential items:

Measuring Tape: A flexible measuring tape, preferably one made of fiberglass or another non-scratching material, is essential for taking accurate measurements around the curves of the exhaust.
Ruler or Calipers: A ruler or calipers (digital or dial) is needed for precise measurements of the pipe diameters. Calipers are more accurate.
Pen and Paper: For recording your measurements.
Work Gloves: To protect your hands.
Safety Glasses: To protect your eyes.
Wrench or Socket Set: For loosening and tightening the exhaust clamps (may not be needed if you’re only measuring).
Penetrating Oil (optional): If the clamps or bolts are rusty, penetrating oil can help loosen them.
Flashlight: To see in tight spaces.
Jack or Lift (optional): Makes access easier.

Step-by-Step Measuring Guide

Follow these steps carefully to measure your Harley-Davidson’s slip-on exhaust accurately. We will cover both the key dimensions to measure and how to measure them. (See Also: Won Hundred Willow Slip On Sneakers )

Step 1: Preparation and Safety

Before you begin, ensure your motorcycle is parked on a level surface. Allow the exhaust to cool down completely to avoid burns. Put on your safety glasses and work gloves.

If you’re planning to remove the old mufflers, you may need to loosen the exhaust clamps. If you are only measuring, you may not need to do this.

Step 2: Identifying the Head Pipe Diameter

This is the most critical measurement, as it determines the size of the slip-on that will fit your head pipes.

Locate the Connection Point: Find where your existing mufflers connect to the head pipes. This is where you’ll be measuring.
Measure the Outside Diameter (OD): Using your calipers or ruler, measure the outside diameter of the head pipe where the muffler slides on. Take several measurements around the pipe to ensure accuracy, especially if there’s any damage or corrosion.
Record the Measurement: Write down the OD measurement in inches or millimeters. It’s best to record it in both.
Common Sizes: Harley-Davidson head pipe diameters often range from 1.75 inches to 2.5 inches, but it’s important to measure your specific bike.

Step 3: Measuring the Muffler Length

Knowing the length of your existing mufflers will help you choose new ones that match your desired look and fit within the space available.

Measure from Tip to Connection: Place your measuring tape along the length of the muffler, from the very end of the exhaust tip to the point where it connects to the head pipe.
Follow the Curve: If the muffler has any curves, follow the contour of the pipe with your measuring tape to get the most accurate measurement.
Record the Measurement: Note down the total length of the muffler in inches or millimeters.

Step 4: Measuring the Inlet Diameter of the Muffler (if Applicable)

Some slip-ons have an inlet diameter that is *slightly* different than the head pipe OD. This is less common but still important to consider.

Locate the Inlet: The inlet is the end of the muffler that connects to the head pipe.
Measure the Inside Diameter (ID): Using your calipers, measure the inside diameter of the muffler inlet.
Record the Measurement: Note this measurement.
Compare: Compare this measurement to the head pipe OD measurement. They should be very close.

Step 5: Inspecting the Mounting Points

Check the mounting points on your existing mufflers. This will influence the type of slip-on exhaust you can install.

Identify Mounting Style: Note whether your mufflers mount with a bracket to the frame, or if they mount directly to the head pipes.
Measure Bracket Location: If applicable, measure the distance between the mounting holes on your current muffler bracket.
Check for Compatibility: Ensure any new slip-ons you choose will have compatible mounting points.

Step 6: Recording Your Measurements

Create a clear record of all your measurements. This will be invaluable when you start shopping for new slip-ons. (See Also: Will Two Brothers Slip On Exhaust Work For Rebel 300 )

Here’s a sample table to use:

Measurement	Value	Units
Head Pipe Outside Diameter	(Record Measurement)	Inches / Millimeters
Muffler Length (Tip to Connection)	(Record Measurement)	Inches / Millimeters
Muffler Inlet Diameter (ID)	(Record Measurement)	Inches / Millimeters
Bracket Hole Spacing (If Applicable)	(Record Measurement)	Inches / Millimeters

Keep this table handy when you start looking for replacement slip-on exhausts.

Understanding Exhaust Terminology

Familiarizing yourself with the common terminology used in the exhaust world can prevent confusion.

OD (Outside Diameter): The diameter of the pipe measured from the outside.
ID (Inside Diameter): The diameter of the pipe measured from the inside.
Header Pipes / Head Pipes: The pipes that connect the engine to the mufflers.
Mufflers / Slip-ons: The part of the exhaust that reduces noise and connects to the head pipes.
Baffles: Internal components within the muffler that control sound and backpressure.
Backpressure: The resistance to exhaust flow, which can affect engine performance.

Choosing the Right Slip-on Exhaust

With your measurements in hand, you’re ready to start shopping for new slip-on exhausts. Consider these factors when making your selection:

Head Pipe Compatibility: The most important factor is that the slip-ons match your head pipe diameter.
Muffler Length: Choose a length that fits your bike’s aesthetics and doesn’t interfere with other components.
Sound Level: Decide how loud you want your exhaust to be. Some slip-ons offer a louder, more aggressive sound, while others are designed for a more subtle tone.
Style and Finish: Consider the overall look of your bike. Choose a finish (chrome, black, etc.) that complements your motorcycle’s style.
Brand and Quality: Research reputable brands that offer high-quality products, such as Vance & Hines, Screamin’ Eagle, Rinehart, and Bassani. Read reviews to get an idea of the product’s performance and durability.
Performance Expectations: Slip-on exhausts can improve performance, but don’t expect dramatic gains. Focus on sound and aesthetics.

Installation Tips

While slip-on exhaust installation is relatively straightforward, here are a few tips to ensure a smooth process:

Read the Instructions: Always read the manufacturer’s instructions carefully before starting the installation.
Use the Right Tools: Ensure you have the necessary tools, including the correct size wrenches and sockets.
Apply Anti-Seize: Apply anti-seize compound to the threads of bolts and studs to prevent them from seizing.
Tighten Clamps Properly: Tighten the exhaust clamps to the recommended torque specifications. Over-tightening can damage the exhaust, while under-tightening can lead to leaks.
Check for Leaks: After installation, start the engine and listen for any exhaust leaks. If you hear a leak, tighten the clamps further.
Re-torque After Riding: After riding the bike for a short distance, re-torque the exhaust clamps, as they may settle and loosen slightly.

Troubleshooting Common Issues

Even with careful planning, you might encounter some issues during the measuring or installation process. Here’s how to address some common problems:

Incorrect Measurements: If the slip-ons don’t fit, double-check your measurements. Measure again and compare them to the specifications of the new exhaust.
Exhaust Leaks: If you hear leaks, check that the clamps are properly tightened and that the exhaust gaskets (if any) are correctly installed.
Difficulty Removing Old Mufflers: If the old mufflers are stuck, try using penetrating oil and gently tapping the pipes with a rubber mallet.
Mounting Issues: Make sure the mounting brackets are aligned correctly. If the holes don’t line up, you may need to adjust the bracket or the muffler position.
Performance Issues: If you experience a loss of performance after installing new slip-ons, it may be due to improper jetting or tuning, especially if you have modified other engine components. Consult a professional mechanic.

Maintenance and Care

Once your new slip-on exhausts are installed, proper maintenance will keep them looking and performing their best. (See Also: Will You Lose Low End With M4 Slip On Fz07 )

Regular Cleaning: Clean your exhaust regularly with a suitable cleaner to remove dirt, grime, and road debris.
Check for Corrosion: Inspect the exhaust for signs of corrosion or rust, especially in areas exposed to the elements.
Inspect Clamps: Periodically check the exhaust clamps to ensure they are secure and properly tightened.
Listen for Changes: Pay attention to the sound of your exhaust. Any changes in sound can indicate a problem that needs attention.

Safety First

Working on your motorcycle can be rewarding, but it’s important to prioritize safety. Always wear appropriate safety gear, including safety glasses and gloves. Work in a well-ventilated area, and never work on a motorcycle while it’s running in an enclosed space. If you’re not comfortable with any part of the process, consult a qualified mechanic.

Beyond Slip-Ons: Other Exhaust Upgrades

While slip-ons are a great starting point, other exhaust upgrades can further enhance your Harley’s performance and sound. These include:

Full Exhaust Systems: Replace the entire exhaust system, including the head pipes and mufflers. These offer the greatest performance gains.
Performance Air Filters: Combine your exhaust upgrade with a high-flow air filter for improved airflow and performance.
Tuning: After installing exhaust upgrades, you may need to tune your motorcycle’s fuel injection system to optimize performance.

Verdict

By following these steps, you can accurately measure your Harley-Davidson’s slip-on exhaust and confidently choose the perfect replacement. Remember to take your time, double-check your measurements, and prioritize safety throughout the process. Enjoy the process of upgrading your bike, and enjoy the improved sound and performance of your new exhaust!

Measuring your Harley-Davidson’s slip-on exhaust is a crucial first step in any upgrade. This guide provides a detailed, step-by-step approach to help you accurately determine the necessary dimensions. From identifying the head pipe diameter to measuring muffler length, you’ll be well-prepared to select the perfect slip-ons.

Remember to record your measurements carefully and compare them with the specifications of the exhaust systems you’re considering. With the right tools and a little patience, you can confidently measure your exhaust and make an informed decision for your Harley-Davidson.

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With your measurements in hand, you’re ready to explore the vast world of Harley-Davidson slip-on exhaust options. Enjoy the process of personalizing your ride and enhancing its performance and sound.