Barnett Clutches offers a range of performance upgrades designed to enhance clutch performance for Harley-Davidson Sportster models. These kits include components such as billet-aluminum pressure plates, specially formulated clutch plates, and spring sets that allow users to tune the clutch to their specific needs. Installation of a Barnett clutch typically involves replacing the factory clutch hub and pressure plate with a Barnett-specific assembly, which may require specialized tools and a basic understanding of motorcycle mechanics. The process can be completed in a home garage with the right equipment and attention to detail.
This article provides a step-by-step overview of the installation process, including required tools, key components, and considerations for ensuring a successful upgrade. The information is based on multiple user experiences, product documentation, and installation guides provided by Barnett Clutches.
Overview of Barnett Clutch Kits
Barnett Clutches offers several types of clutch kits for Harley-Davidson Sportster models, including the Scorpion clutch and the Extra Plate Kit. These kits are designed to improve clutch capacity, engagement smoothness, and overall performance. The Scorpion clutch, for example, uses six coil springs and a billet-aluminum pressure plate to provide a more linear engagement compared to the stock diaphragm spring system. This allows for better control during acceleration and deceleration.
The Extra Plate Kit increases the surface area of the clutch by adding an additional friction and steel plate, which enhances torque capacity without requiring modifications to the existing clutch assembly. This kit is particularly useful for riders who frequently carry heavy loads or operate in high-stress conditions. Additionally, Barnett offers diaphragm springs that are approximately 25% heavier than stock, allowing for a more aggressive clutch engagement when needed.
All Barnett clutch kits are designed to be compatible with the 1986–1990 four-speed Evo Sportster models. Installation typically requires removing the stock clutch hub and replacing it with a Barnett-specific hub that fits within the factory clutch basket. This process may require the use of a hydraulic press to remove the factory clutch hub and install the new one. Users are advised to refer to the factory service manual for their specific model when performing these steps.
Tools and Materials Required for Installation
Before beginning the installation process, it is essential to gather all the necessary tools and materials. Based on the information provided in user reports and manufacturer documentation, the following tools are typically required:
- Ball end Allen wrenches
- Mechanical picks
- In-lb torque wrench
- Needle-nose pliers
- 10mm socket or combo wrench (for removing the Stebel horn, if installed)
- Hydraulic press (to remove and install the clutch hub)
- Oil pan (to catch any oil leakage during the process)
- Corrugated cardboard or similar material (to trace the clutch cover bolt pattern)
- Small screwdriver (for poking holes in the cardboard to align bolts)
- Side stand for the motorcycle
In addition to these tools, users should ensure they have a clean, well-lit workspace and a basic understanding of clutch mechanics. It is also recommended to have the factory service manual for the specific motorcycle model on hand, as it may contain critical information about torque specifications and component alignment.
Step-by-Step Installation Process
The installation process for a Barnett clutch typically involves several key steps, including removing the clutch cover, disassembling the stock clutch, and installing the new Barnett components. Below is a detailed overview of the process based on user experiences and manufacturer instructions.
Preparing the Motorcycle
Before beginning the installation, it is important to prepare the motorcycle for the procedure. This includes placing the bike on the side stand and positioning an oil pan under the clutch cover side to catch any oil that may leak during the process. Users should also ensure that the transmission is in neutral and that the bike is stable throughout the installation.
If a Stebel horn is installed, it should be removed using a 10mm socket or combo wrench. The horn can then be temporarily hung from the rear footboard using a piece of coat hanger wire to prevent interference during the installation.
Removing the Clutch Cover
The next step involves removing the clutch cover. Users should take note of the bolt locations, as there are typically two different lengths of bolts used to secure the cover. To keep track of the bolt pattern, it is recommended to trace the shape of the cover onto a piece of corrugated cardboard, including the oil fill location. A small screwdriver can be used to poke holes in the cardboard, allowing the bolts to be inserted in the correct positions.
Once the cover is removed, users should inspect the gasket for any signs of wear or damage. In some cases, the gasket may remain intact and can be reused. However, if it shows signs of deterioration, it should be replaced with a new one to ensure a proper seal.
Disassembling the Stock Clutch
With the clutch cover removed, the next step is to disassemble the stock clutch. This involves removing the six bolts that secure the spring and pressure plate. Once the bolts are removed, the spring and pressure plate can be carefully taken out. Users should be cautious during this step to avoid damaging any internal components.
In some cases, a hydraulic press may be required to remove the factory clutch hub from the basket. This is particularly important for models that use a factory hub that is pressed into the basket. Once the factory hub is removed, the Barnett clutch hub can be installed in its place. Users should ensure that the hub is properly seated and aligned with the basket before proceeding.
Installing the Barnett Clutch Components
After the factory hub has been removed and the Barnett hub has been installed, the next step is to install the new clutch components. This includes the billet-aluminum pressure plate, the specially formulated clutch plates, and the spring sets. Users should follow the manufacturer's instructions carefully to ensure that all components are installed correctly.
For the Extra Plate Kit, users should add the additional friction and steel plate to increase the surface area of the clutch. This will enhance the torque capacity without requiring any modifications to the existing assembly. The diaphragm spring can also be replaced with a heavier spring to provide a more aggressive clutch engagement.
Once all components have been installed, the pressure plate and spring should be reassembled, and the bolts should be tightened to the specified torque. It is important to refer to the factory service manual for the correct torque specifications to avoid over-tightening or under-tightening the bolts.
Reassembling the Clutch Cover
With the new clutch components installed, the next step is to reassemble the clutch cover. Users should ensure that the gasket is properly seated and that all bolts are tightened to the correct torque. It is also important to verify that the oil fill location is correctly positioned and that there are no leaks.
Once the cover is reinstalled, the bike should be inspected for any signs of oil leakage. If any leaks are detected, the gasket should be replaced or the bolts should be retightened to the correct torque. It is also recommended to perform an oil change after the installation to ensure that the clutch operates smoothly and efficiently.
Post-Installation Considerations
After completing the installation, there are several additional considerations that users should keep in mind to ensure optimal performance and longevity of the new clutch system.
Testing and Adjustment
Before riding the motorcycle, it is important to test the clutch engagement and make any necessary adjustments. This includes checking the clutch lever free play and adjusting it if necessary. Users should also test the engagement point to ensure that it is smooth and consistent.
In some cases, users may need to adjust the spring tension to achieve the desired level of engagement. This can be done by selecting a different spring set from the Barnett kit. Users should refer to the manufacturer's instructions for guidance on selecting the appropriate spring tension for their specific needs.
Maintenance and Care
Proper maintenance is essential for ensuring the longevity of the new clutch system. This includes regular inspections for signs of wear, such as cracked gaskets, worn clutch plates, or loose bolts. Users should also ensure that the clutch is properly lubricated and that the oil level is maintained at the correct level.
It is also important to follow the manufacturer's recommendations for oil changes and filter replacements. This will help to ensure that the clutch operates smoothly and efficiently over time.
Conclusion
The installation of a Barnett clutch on a Harley-Davidson Sportster model is a viable upgrade for riders seeking improved performance and reliability. By following the step-by-step process outlined in this article, users can successfully install the new clutch components and enjoy enhanced clutch engagement, increased torque capacity, and smoother operation. The key to a successful installation is careful preparation, attention to detail, and adherence to manufacturer guidelines.