Emission Control Systems; Source Of Emissions; Exhaust Emission Control System; Crankcase Emission Control System - Honda 1998 VT750C Service Manual

GENERAL INFORMATION
EMISSION CONTROL SYSTEMS
The U.S. Environmental Protection Agency, Transport Canada, and California Air Resources Board (CARB) require
manufacturers to certify that their motorcycles comply with applicable exhaust emissions standards during their useful life,
when operated and maintained according to the instructions provided, and that motorcycles built after January 1, 1983
comply with applicable noise emission standards for one year or 6,000 km (3,730 miles) after the time of sale to the ultimate
purchaser, when operated and maintained according to the instructions provided. Compliance with the terms of the
Distributor's Limited Warranty for Honda Motorcycle Emission Control Systems is necessary in order to keep the emissions
system warranty in effect.
SOURCE OF EMISSIONS
The combustion process produces carbon monoxide and hydrocarbons. Control of hydrocarbons is very important because,
under certain conditions, they react to from photochemical smog when subjected to sunlight. Carbon monoxide does not
react in the same way. but it is toxic.
Honda Motor Co., Ltd. utilizes lean carburetor settings as well as other systems, to reduce carbon monoxide and hydrocarbons.
EXHAUST EMISSION CONTROL SYSTEM
The exhaust emission control system is composed of a lean carburetor setting, and no adjustments should be made except
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 emission into the atmosphere.
Blow-by gas is returned to the combustion chamber through the air cleaner and carburetor.
CRANKCASE BREATHER
COVER
DRAIN TUBE
-
CARBURETOR
¢:J:
FRESH AIR
.. : BLOW-BY GAS
1-34