Silencer
Removal
1 On YZF models, if required for improved clearance and to avoid the possibility of damage, remove the right-hand fairing side panel (see Chapter 8, Section 3).
2 Slacken the clamp bolt securing the silencer to the downpipe assembly (see illustration).
3 Unscrew and remove the silencer mounting bolt, then release the silencer from the exhaust downpipe assembly (see illustration).
4 Remove the sealing ring from the end of the silencer or downpipe assembly and discard it as a new one should be used. Installation
5 Fit the new sealing ring onto the end of the downpipe assembly.
6 Fit the silencer onto the downpipe assembly, making sure it is pushed fully home. Align the silencer mounting bracket at the rear and install the bolt, but do not yet tighten it.
7 Tighten the clamp bolt to the torque setting specified at the beginning of the Chapter, then tighten the silencer mounting bolt to the specified torque (see illustrations 3.2 and 13.3).
8 Run the engine and check the system for leaks.
The pictures don't show any gasket or sealing ring.
Opinions are like A**holes, Everyone has one. Some people seem to have more than one though which is a bit odd.