Suzuki GS850G Service Manual page 445

a
GENERAL EMISSION lNFORMATION
There are three different types of regu tated exhaust emissions. They are:
Hydrocarbons
I
HC)
Carbon Monaxide
(CO)
Oxides of Nitrosen
(NOx)
Automobiles must meet specific emission standards for all three of theie pollutants. Motorcycles
must
only meet the requirements for the following:
Hydrocarbons 4HC)
Carbon Monoxide (CO)
MC 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 combustion cycle as a result of a rich airlfvel
mixture. The only way that CO can be produced is by the combustion cycle.
Total MOx
emissions from
all motorcycles is considered negligible. The €PA states that total NOx emis-
sion from motorcycles by 1990 will only amount to approximately 0.5%. N0x i s formed during the
combustion process
at
high corn bustion chamber temperatures.
CARBON MONOXIDE
Carbon monoxide is a product of an incomplete combustion cycle. 60 is measured in grams per mile
or
kilometer and also in percentase
(%I
@ The most common
cause
of CO i s rich carburetion. As the mixture i s richened excerrively, the
CO
amount increases proportionately. Engine oil is also
a
hydrocarbon, so engine problems which lead
to
oil
burning increase carbon monoxide.
CARBURETION MAtFUNCTlON
1. Air Cleaner
-
Dirty or over oiled.
2. Idle Mixture
-
Adjusted incorrectly.
3. Idle Speed
-
Too high or low.
4.
Fuel
Level
-
Sticking float, leaking needle, incorrect setting.
5. Choke
-
Leaking or linkage sticking.
6, Synchronization
-
Improper balance on multi cylinders.
ENGINE MALFUNCTIONS
@
1. Valve Seals -
Leaking or torn.
2. Valve Guide
-
Worn and leaking excess oil.
3. Gaskets -
Leaking oil into combustion chamber.