Catalytic Silencer - APRILIA CLASSIC 125 - 1997 Manual

CATALYTIC SILENCER

a
Avoid parking the vehicle cata-
lytic version near dry brush
wood or in places easily accessi-
ble to children, as the catalytic silencer
becomes extremely hot during use; be
very careful and avoid any kind of con-
tact before it has completely cooled
down.
26 use and maintenance Classic 125
The catalytic Classic 125 is fitted with a si-
lencer with metal catalytic converter of the
"platinum-rhodium bivalent" type.
This device provides for the oxidation of
the CO (carbon monoxide) and of the HC
(unburned hydrocarbons) contained in the
exhaust gases, changing them into carbon
dioxide and steam, respectively.
Due to the catalytic reaction, the high tem-
perature reached by the exhaust gases
makes for the burning of the oil particles,
thus keeping the silencer clean and elimi-
nating the exhaust fumes.
To have the catalytic converter function
2
correctly and for long and to reduce possi-
ble problems regarding the soiling of the
thermal unit and of the exhaust, it is neces-
sary to avoid covering long distances with
the engine running at constantly low rpm.
It is sufficient to alternate these periods
with periods in which the engine runs at rel-
atively high rpm, even if only for a few sec-
onds, but rather frequently.
What has been stated above assumes par-
ticular importance for the cold starting of
the engine: in this case, in order to reach a
rpm regime sufficient to enable the "prim-
ing" of the catalytic reaction, just make
sure that the temperature of the thermal
unit has reached at least 50˚C, which gen-
erally occurs a few seconds after starting
the engine.
a
Do not use leaded petrol, since it
causes the destruction of the
catalytic converter.