How to Quiet a Motorcycle Mufflerby Chris Gilliland
"Loud pipes save lives" is an age-old proverb in the motorcycle community, but whoever thought that up forgot to mention that loud pipes also alienate neighbors and attract unwanted attention from law enforcement. This is true even for off-road motorcycles, which must meet noise level requirements in order to ride on public trails. While excessive noise can be created intentionally, loud pipes can also be a sign that the silencing packing material within the muffler has deteriorated. Fortunately, making the police, and your neighbors, happy can be a simple matter.
Repacking the Muffler
Drill out the rivets securing the muffler's end cap using the bit provided in the re-pack kit.
Remove the muffler's inner core carefully, pulling out any remaining exhaust packing material.
Wrap the new exhaust packing material around the inner core. The material should be wrapped snugly without over-tightening to allow the exhaust gases to expand into the packing.
Slide the freshly wrapped core back into the muffler.
Re-attach the end cap using the pop rivets included in the re-pack kit.
Installing a Slip-in Baffle
Measure the inner diameter of your muffler. Universal slip-in baffles are available in a range of sizes to fit the multitude of aftermarket exhausts. Alternatively, many exhaust brands offer a slip-in baffle specific to their products.
Clean the inner rim of the muffler.
Remove the mounting screw on the baffle.
Slide the baffle into the muffler gently, checking for placement.
Align the baffle with the mounting hole on your muffler. If a mounting hole is not present, it is recommended to drill a small hole into the muffler.
Apply a drop of LOC-TITE onto the mounting bolt and screw the baffle into place.
- A freshly re-packed muffler may emit sparks when the bike is started for the first time, this is normal. The sparking will stop in a few minutes as the exhaust packing "seasons." If not provided, it is recommended to drill a small hole into the end of your pipe where you plan on installing the baffle. This hole will be used to secure the baffle with a bolt to prevent ejection under pressure. There is nothing wrong with knowing your limits. If you are not confident you can complete these projects, have the work done by a qualified technician.
- Keep the area directly behind the motorcycle clear when starting after installation. Exhaust gases may force the baffle from the pipe if it is not properly secured and could cause injury. Also, fresh packing may partially ignite, emitting hot sparks from the muffler. Stand back to prevent burns. Follow any manufacturer instructions provided. Don't rush or you will cause more problems than needed.
Items you will need
- Power drill
- Slip-in baffle
- Exhaust packing kit (these kits usually include any rivets or drill bits required)
- Rivet tool
- The Professional Motorcycle Repair Program; Professional Career Development Institute; 1995
- How-To: Pack It In; Motorcyclist Magazine Online
- Harley-Davidson Tries To Quiet Motorcycle Noise - Loud Pipes' Cost; Motorcycle Cruiser Magazine Online