Suzuki GS850G Service Manual page 408

GENERAL EMISSION INFORMATION
There are three different types of regulated exhaust emissions, They
are:
Hydrocarbons
l
HCF
Carbon Monoxide
ICOE
Oxides of Nitrogen (NOx}
Automobiles must meet specific emission standards for all three of these pollutants. Motorcycles must
only meet the requirements for the following:
Hydrocarbons
(
HC)
Carbon Monoxide (C01
@
HC exhaust emissions are basically unburned fuel vapors which have
passed through the engine and
es-
caped the combustion process.
CO exhaust
emissions are formed during an incomplete ctlrnbustion cycle as a result of a rich airlfuel
mixture. The
only way
t h a t CO can be
produced is by
the combustion
cycle.
Total NOx emissions from all motorcycles is considered negligible. The EPA states t h a t total
NOx
emis-
sion from motorcycles by 1990 will only amount to approximately
0,5%. NOx is formed during the
combustion process a t high combustion chamber temperatures.
CARBON MONOXIDE
Carbon monoxide is a product of an incomplete combustion cycle. CO is
measured
in
grams
per mile or
kilometer and also in percentage (%)
The
most
common cause of
CO
is rich carburetion. As the mixture is richened excessively, the
CO
amount increases proportionately. Engine
oil
i s also
a hydrocarbon, so
engine problems which
lead to oil
burning increase carbon monoxide.
CARBURETlON MALFUNCTION
1. Air Cleaner
-
Dirty or over oiled.
2. ldle Mixture -
Adjusted incorrectly.
3. ldle Speed
- Too high
or low.
4. Fuel Level
-
Sticking float, leaking needle, incorrect setting.
5 . Choke
-
Leaking or linkage sticking.
6*
Synchronization
-
Improper balance an rnulti cylinders.
@
ENGINE MALFUNCTIONS
1. Valve Seals
-
Lea'king or torn.
2. Valve Guide
-
Worn
and leaking excess oil.
3.
Gaskets
-
Leaking oil into combustion chamber.