Kohler Command PRO ECH749 Service Manual

5.15
Section 5
EFI Fuel System
5
CONDITION POSSIBLE CAUSE CORRECTION
Low voltage output Shorted sensor or sensor circuit Replace sensor or repair wiring
Shorted lead wire
Wiring shorted to ground
Contamination of air reference
Remove source of external
contamination, protect air
reference area
Air leak at sensor or gasket,
sensor upper shield damage
Use recommended torque at
installation, replace gasket or
sensor
Revise application exhaust
Shield sensor from damage
High voltage output Silica poisoning Replace sensor
Contaminated gasoline Use high quality fuel
Engine problem; misfi re Correct cause of misfi re
Excessive rich air/fuel ratio Correct air/fuel ratio
Wiring shorted to voltage Repair wiring
Open circuit, no activity from
sensor
Broken element Replace sensor
Sensor dropped
Hard blow to engine or exhaust
system
Defective sensor
Thermal shock
Slow time response Open heater circuit Replace sensor
Improper handling
Carbon deposits
Improper fueling Correct fueling
Incorrect or contaminated fuel Use high quality fuel
Excessive engine oil consumption
causing exhaust contamination or
other exhaust side contamination
Correct engine condition
Heater circuit open/shorted or out
of specifi cation
Repair short in harness wires,
replace sensor
Oxygen Sensor Symptoms and Corrections

Kohler Command PRO ECH749 Specifications

General

Fuel System	Carburetor
Starter	Electric
Governor Type	Mechanical
Lubrication System	Full Pressure
Fuel Type	Gasoline
Crankshaft Orientation	Horizontal
Bore	3.27 in (83 mm)
Cooling System	Air
Oil Type	SAE 10W-30
Spark Plug Gap	0.030 in (0.76 mm)
Valve Clearance - Intake	0.004 - 0.006 in (0.10 - 0.15 mm)
Crankshaft Type	Varies by model
Crankshaft Thread Size	Varies by model
Crankshaft Length	Varies by model
Crankshaft Diameter	Varies by model
Type	Overhead Valve (OHV)