How to Repack a Yoshimura ATV Exhaust
Yoshimura has offered world-class exhaust systems and performance parts since the 1970s, boosting the performance of racing machines on the road and in the dirt. But even the most advanced exhaust system requires some basic maintenance: the often-forgotten replacement of the muffler packing. Over time, heated exhaust gases deteriorate the steel wool and fiberglass material in the muffler, generating louder exhaust noise and lowering the performance of your ATV. Fortunately, Yoshimura offers a repacking kit that allows an ATV rider with minimal technical knowledge the ability to repack the muffler in his own garage.
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Things You'll Need
- Safety glasses
- Yoshimura muffler repack kit
- Soft work pad
- Electric drill with 3/8-inch or 1/2-inch chuck
- No. 9 drill bit
- Pin punch for a .20-inch hole
- Hammer
- Mallet, soft-faced
- Work gloves
- Rivet gun
- RTV silicone sealant
- Towel or rag
Instructions
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1
Remove the exhaust muffler from the ATV and place it on a soft work pad to prevent damaging the exterior of the muffler.
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2
Insert the No. 9 drill bit into the electric drill's chuck and drill out the rivets of the silencer's end cap. Be sure to drill directly into the center of each rivet. Repeat the process on the inlet cap at the base of the muffler.
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3
Place the pin punch over the remains of each rivet and tap the punch with a hammer to dislodge the rivets from the muffler. This step must be done on both ends of the muffler.
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4
Remove the metal rivet bands from both ends of the muffler and place in a safe location.
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5
Remove the end cap by tapping at the base of the end cap outwards with a soft-faced mallet, rotating the muffler to tap the cap off evenly. Repeat the process to remove the inlet cap, tapping on the inlet tube lightly while rotating the muffler.
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6
Remove the inner baffle by tapping towards the end cap side of the muffler with a soft-faced mallet. Pull out the baffle by hand once it is loose.
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7
Unwrap the old packing that surrounds the baffle, then unwind the steel wool packing wound around the inner core of the baffle.
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8
Place the baffle onto a layer of fresh "pillow" packing and wrap snugly. Taking note of the end cap side of the muffler shell, slide the baffle into the muffler. Press in any packing material that may have popped out of the muffler ends.
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9
Refit the inlet cap, tapping it into place with a soft-faced mallet. Then place the metal rivet band around the inlet cap and muffler, placing a single rivet at the overlapping ends of the band. Fit the remaining rivets in place, then install with a rivet gun.
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10
Refit the end cap, tapping it into place with a soft-faced mallet if necessary. Then place the metal rivet band around the end cap and muffler, placing a single rivet at the overlapping ends of the band. Fit the remaining rivets in place, then install with a rivet gun.
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11
Apply a thin bead of RVT silicone sealant to the end cap and inlet cap seams. Wipe away any excess sealant with a clean towel or rag.
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12
Reinstall the muffler onto your ATV.
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1
Tips & Warnings
A freshly repacked 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."
Yoshimura recommends replacing the packing after every 10 to 15 hours of use.
If you are not confident you can complete these projects, have the work done by a qualified technician.
Wear proper eye protection to prevent eye injuries.
Keep the area directly behind the ATV clear when starting after installation. Exhaust gases may may partially ignite fresh packing, emitting hot sparks from the muffler. Stand back to prevent burns.
