Honda CG150 Titan ES Owner's Manual page 115

IV
Noise Level
Your motorcycle is powered by a reciprocating engine that
meets current standards regarding noise emission control
for automotive vehicles. Several moving parts are used in
the engine manufacturing process. The mechanism has
manufacturing tolerances that strictly follows engineering
standards and production quality control.
Depending on the tolerance variation, some engines may
sound different when compared to other engines of the
same displacement. This variation is normally noted when
the engine temperature changes. This is a normal
condition.
ATTENTION
Do not remove any attaching device and use only
Honda genuine parts for replacement to avoid
unpleasant noises.
Vibrations
This motorcycle is equipped with a reciprocating engine,
which is a typical internal combustion automotive engine
(Otto cycle). Its components move reciprocally
synchronized with the crankshaft. During operation,
vibrations and noise may occur. This is a normal condition.
These vibrations are transmitted throughout the motorcycle.
They may be stronger due to the geometry of each
component, such as handlebars, rear fender, turn signals,
fuel tank, etc.
Furthermore, vibrations can also be noticed when riding on
rough surfaces or due to the aerodynamic effect (air impact
with several components or pilot).
These vibrations are not considered an abnormal condition.
They are a normal characteristic of an automotive vehicle
and therefore are not covered by Honda Limited Warranty.
During motorcycle operation, these vibrations may lead to
bolts and component loosening.
ATTENTION
When riding the motorcycle on rough surfaces, check
the fasteners for tightness to avoid unpleasant
vibrations.
Owner's Manual