Kohler SFGLD480 Operation & Maintenance Manual page 211

As a result, it is necessary to increase exhaust emission controls with a view to making any correction of the
air/fuel ratio that may be required to prevent the engine from running at risk.
3- Unusual emission values can denote any of different problems with the engine, according to the component of
the exhaust gases which is out of standard and the engine behaviour. For instance:
High oxygen level: denotes ignition problems (old spark plugs, broken or defective spark plug, faulty
-
connection of a wire, failure of the ignition unit...). It is associated with a high level of Total Hydrocarbons
(THC), if measured. Also, the exhaust temperatures will be lower on the affected cylinder bank and possible
unbalance will be observed between the two banks of Vee engines.
The engine will not reach its rated power, although the emission levels show a good mixture: This can be
-
caused by air filter plugging or by problems with the throttle valve.
The engine will not reach its rated power and the emission levels denote a very poor mixture: This is due to
-
engine carburation faults or problems with the fuel system (low fuel pressure, dirty fuel filter, valves not
opening correctly, ...). Also, the exhaust temperatures will be lightly lower and the throttle valve will be fully
open.
PRODUCT INFORMATION
IO-G-M-40-001e
GAS ENGINES AND ETHANOL ENGINES CARBURATION
4.1.44
INDEX DATE
D
July 2015
O&M_2.002211.810_A_10_2016
Dep.2
2/2