Remove the exhaust stud nuts, each with one flat washer and one lockwasher. Remove the bolt holding the muffler to the frame under the edge of seat.
Pull the muffler forward and off.
Take out the bolts holding the spark arrestor and baffle tube in the rear of the muffler.
Clean the spark arrestor and the baffle tube of as much carbon and debris as possible. Be sure all the holes in the baffle tube are clean.
Use a new exhaust gasket at the cylinder to prevent leaks.
Tighten the exhaust stud nuts to 0.35 to 0.50 kg-m (2.5 to 3.5 lb-ft) of torque.