Kärcher HDS 3.9/30 Operator's Manual page 16

PROBLEM
BURNER WILL
NOT LIGHT
(continued from
previous page)
FLUCTUATING
PRESSURE
MACHINE
SMOKES
WHILE
BURNER UNIT
IS RUNNING
OR
UNIT SMOKES
AT COLD-START
ONLY WHEN
BURNER
IS OFF
16
TROUBLESHOOTING
POSSIBLE CAUSE
Flex coupling slipping on fuel
pump shaft or burner motor shaft
On-Off switch defective
Heavy sooting on coil and burner
can cause interruption of air fl ow
and shorting of electrodes
Improper electrode setting
Fuel not reaching combustion
chamber
Clogged burner nozzle
Thermostat faulty or slow engine
speed
Flow switch malfunction
Flow solenoid malfunction
Valves worn
Blockage in valve
Pump sucking air
Worn piston packing
Gasoline engine altitude
Improper fuel or water in fuel
Improper air adjustment
Fuel pressure is low <140 psi for
burner
Burner nozzle is plugged or dirty
Burner nozzle spray pattern is
faulty
Heavy accumulation of soot on
coils and burner assembly
Misaligned electrode setting
Obstruction in smoke stack
Low engine RPM
Fuel Pressure is too high for
clean burn (fuel PSI above 140
and below 200) and smokes
when burner is off
HDS 600-606
SOLUTION
Replace if needed.
Check for electrical current reaching burner assem-
bly with burner switch on.
Clean as required.
Check and reset according to diagram in Operator's
Manual.
Check fuel pump for proper fl ow.
Check solenoid fl ow switch on machines with spray
gun control, for proper on-off fuel fl ow control.
Clean as required.
Increase engine RPM to increase voltage.
Remove, test for continuity and replace as needed.
Replace if needed.
Check and replace if necessary.
Check and replace if necessary.
Check water supply and air seepage at joints in suc-
tion line.
Check and replace if necessary.
T h e g a s o l i n e e n g i n e i s p r e s e t fo r o p e ra -
tion at altitudes below 1000 ft above sea level.
If operated at higher altitudes, it may be necessary to
install a high altitude main jet in the carburetor. Contact
your local authorized engine sales and service center
for details.
Drain tank and replace contaminated fuel
Readjust air bands on burner assembly
Adjust fuel pump pressure to specifi cations
Replace nozzle. Check parts breakdown
for nozzle size
Replace nozzle. Check parts breakdown
for nozzle size
Remove coils and burner assembly,
clean thoroughly Call local dealer
Realign electrodes to specifi cations
Check for insulation blockage or other
foreign objects
Increase RPM to correct specs. See serial plate
Reduce fuel pressure PSI/Increase air band set for
cleaner without max water heat loss
• 9.800-080.0-AB