Segway Villain SX10 Owner's Manual page 114

SOURCE OF EXHAUST EMISSIONS
The combustion process produces carbon monoxide(CO),oxides of nitrogen(NOx)and
hydrocarbons(HC).Control of hydrocarbons and oxides of nitrogen is very important
because, under certain conditions, they react to form photochemical smog when
subjected to sunlight. Carbon monoxide does not react in the same way, but it is
toxic.
EXHAUST EMISSION CONTROL SYSTEM
The exhaust emission control system includes a PGM-F system and oxygen sensor.
No adjustments to this system should be made although periodic inspection of the
components is recommended.
The exhaust emission control system is separate from the crankcase emission
control system.
CRANKCASE EMISSION CONTROL SYSTEM
The engine is equipped with a closed crankcase system to prevent discharging
crankcase emissions into the atmosphere. Blow-by gas is returned to the
combustion chamber through the air cleaner.
NOISE CONTROL SYSTEM
Do not modify the engine,air intake or exhaust components, in order to meet local
noise level requirements.
7-1