Emission Control Systems - Honda CRF50F 2004-2015 Service Manual

GENERAL INFORMATION
EMISSION CONTROL SYSTEMS
The U.S. Environmental Protection Agency (EPA), and the California Air Resources Board (CAR B) require that off-road
motorcycle comply with applicable exhaust emissions standards during its useful life, when operated and maintained
according to the instruction provided.
SOURCE OF EMISSIONS
The combustion process produces carbon monoxide, oxides of nitrogen , and hydrocarbons. Controlling 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.
Honda Motor Co., Ltd. utilizes various systems to reduce carbon monoxide, oxides of nitrogen , and hydrocarbons.
EXHAUST EMISSION CONTROL SYSTEM
The exhaust emission control system is composed of appropriate carburetor setting, no adjustments should be made
except for high altitude setting and idle speed adjustment with the throttle stop screw. 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.
~Iow-by
gas is returned to the combustion chamber through the air cleaner and carburetor.
AIR CLEANER
CARBURETOR --_ _ _ _
CRANKCASE BREATHER DRAIN HOSE
CRANKCASE BREATHER
STORAGE TANK
• BLOW-BY GAS
¢::=
FRESH AIR
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