Suzuki GS850G Service Manual page 314

GENERAL EMISSION INFORMATION
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There are three different types of regulated exhaust emissions. They are:
Hydrocarbons (HC)
Carbon Monoxide
(CO)
Oxides ef Nitrogen (NOx)
Automobiles must meet specific emission standards for all three of these pollutants, MotorcycSes must
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only meet the requirements for the following:
Hydrocarbons (HC)
Carbon Monoxide (CO)
HC exhaust emissions are basically unburned fuel vapors which have passed through the engine and es-
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caped the combustion process.
CO exhaust emissions are formed during an incomplete combustion cycle as a result of a rich airJfuel
mixture. The only way that CO can be produced is by the combustion cycle.
Total
NOx emissions from all motorcycles is considered negligible. The EPA states that total NOx emis-
sion from motorcycles by 1990 will only amount t o approximately 0.5%. NOx is formed during the
combustion process
a t
high combustion chamber temperatures.
CARBON MONOXIDE
Carbon monoxide i s a product of an incomplete combustion cycle.
CO i s
measured in grams per mile
or
kilometer and also in percentage (%)
The most common cause o f CO i s 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 031
burning increase carbon monoxide,
CARBURETION MALFUNCTION
1. Air Cleaner
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Dirty or over oiled.
2. IdleMixture-Adjusted incorrectly,
3. Idle Speed
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Too high or low.
4. Fuel
Level
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Sticking float, leaking needle, incorrect setting.
5. Choke- Leaking or linkagesticking.
6. Synchronization
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Improper balance on multi cylinders.
ENGINE MALFUNCTIONS
1. Valve Seals
-
Leaking or torn.
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2.
Valve Guide
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Worn and leaking excess oil.
3.
Gaskets
- Leaking ail into combustion chamber.