❏ Aftermarket exhausts increase the
performance of your machine and
make it sound more aggressive. After
20 to 30 hours of riding, four-stroke
muffler packing starts to deteriorate,
resulting in loss of power and, in
some cases, an obnoxiously loud
machine. On two-stroke machines,
after hours of use, the packing can get
saturated in oil, clogging the exhaust
flow. We picked up some new pack-
ing from FMF to show you how to
repack your muffler on two- and four-
stroke machines. For our Yamaha
Blaster, we got their $16.99 two-stroke
packing, and for our Honda 400X, we
picked up their $21.99 pillow packing
and $26.99 race packing.
Align the new packing with the longest dimension running the length of the core. Wrap the core and secure the packing with a
strip of 1/2-inch-wide masking tape near each end. The packing should be snug but not too tight, as this may actually increase
the noise level.
Before reinstalling the inner-core assembly into the muffler can, apply a thin bead of high-temp silicone on the front end cap
where it makes contact with the canister.
Slide the inner-core assembly into the canister, making sure it is fully seated into the rear end cap. Wipe off any excess silicone, and reinstall the Allen screws with a small dab of anti-seize on each thread. Tighten each screw an additional 1/4 turn
once the screw has made contact with the canister. Allow sufficient time for the silicone to cure before starting the engine.
Now that your muffler is reassembled with new packing and the silicone is dry you can reinstall the exhaust back on your
machine and go out on adventures. ❏