S&S CYCLE - 550-0664 - 4-1/2” MK45 Performance Mufflers - Black Thruster
The S&S CYCLE 550-0664 is a purpose-built muffler designed and tested to perform correctly in the conditions and applications it was made for. Mk45 4-1/2” Touring Mufflers are the result of decades of riding, racing and tuning. Combines both a stainless steel baffle and RaceTEX cartridge packing, giving you a level of quality that holds up across the full service life of the component. Create a deep rumble and improved horsepower and torque, all while adding a unique look with styled aluminum endcaps. Removable dB reducer. Not for Trike applications. For riders who know the difference quality components make, the 550-0664 is the right call. Sold as a pair.
Features
- Mk45 4-1/2” Touring Mufflers are the result of decades of riding, racing and tuning
- Combines both a stainless steel baffle and RaceTEX cartridge packing
- Create a deep rumble and improved horsepower and torque, all while adding a unique look with styled aluminum endcaps
- Removable dB reducer
- Made in U.S.A.
- Not for Trike applications
Specs
- End Cap Color/Finish: Black
- Muffler Color/Finish: Chrome
- End Cap Material: Aluminum
- Product Name: Muffler
- Outer Diameter: 4-1/2”
- Riding Style: Street
- Type: Slip-On
- End Cap Color/Finish: Polished
- Model: MK45
- Units: Pair
- End Cap Style: Thruster
Frequently Asked Questions - S&S CYCLE - 550-0664 - 4-1/2” MK45 Performance Mufflers - Black Thruster
How do I know if this part fits my vehicle?
Check the fitment information listed on this page against your exact year, make, model, and (where applicable) trim, engine size, or configuration. If your exact vehicle isn't listed, or you're not sure, use the product chat on this page or contact our support team before ordering - we're glad to help confirm fitment.
What does it mean if a product is listed as universal fit?
Universal fit means the product is designed to work across a range of vehicles, not that it's guaranteed to fit every one. Compare the listed measurements, mounting requirements, and connector or hardware specs against your specific vehicle before ordering, since some installations may need additional hardware or minor fabrication.
Where can I find installation instructions for this product?
General installation notes are provided above where available. For detailed step-by-step instructions, refer to the manufacturer's documentation included with the product, or use the product chat on this page for questions about difficulty, required tools, or whether professional installation is recommended.
What if I have more questions about this product?
Use the product chat on this page for fitment, specs, installation, and compatibility questions, or contact our support team directly for help before you order.
