Hydrocarbons; Ignition System Malfunctions; Mixture-Related Malfunctions - Suzuki GS850G Service Manual

EMISSION CONTROL 8- REGIILA 7'10N.Y
HYDROCARBONS
Hydrocarbons are unburnt gasoline vapors and can he measured in two differenct
ways.
The
first is
to
measure the weight of the pollutants over
a
specific distance such
as
grams per mile or grams per
kilometer. The second method is to measure the concentration
of
HC
in the exhaust gas in parts per
million
(PPM).
The most common cause of high HC emissions are ignition system problems. Tf the ignition system
fails to
ignite
the fuel mixture properly, then
raw gasoline
vapors will pass through the engine into
the exhaust system. Listed are the most common ignition problems
which occur and which can
affect HC emission output.
1 GNITlON SYSTEM MALFUNCTIONS
1 .
Spark plugs-Fouled, dirty, improper
type
or improperly gapped.
2. Contact Points-improperly adjusted, pitted,
worn
or sticking,
3. Ignition Timing-Advanced or Retarded.
4,
Timing advance-Too fast or too slow an
advance
rate.
5. Battery-Low charge
or faulty.
Carburetion can also lead to high HC emissions if the
mixture
is either
excessively rich or
ex-
cessivel y lean.
MIXTURE-RELATED MALFUNCTIONS
1. Air CIeaner-Dirty, over oiled or tern.
2. Jets-Clogged, constricted or incorrect
size.
3. Float Level-Level too low
(lean) or too high (rich).
4. Choke-Leaking choke plunger or sticking linkage.
5 .
Air Leaks-Intake
manifolds, engine gaskets and
other sealing surfaces.
6. Synchroniza tion-Unbalanced on mu1 ti-cylinder machines.
7 . Exhaust System-Restricted flow or improper exhaust system.
Engine wear
or
damage
can also cause
high HC emission,
1
.
Rings-Low compression, leakage
into crankcase.
2. Valves-Improper adjustment, bent
stem
or burnt.
3. Gaskets-Leaking, loss of compression.
4. Crank seals-leaking.
5 . Oil Consumption-Worn valve guides, worn
rings, clogged crankcase breather.
6 . Oil-lmproper
engine oil.