9.800-079.0 • Rev. 01/18
OPERATOR’S MANUAL
PRESSURE
WASHER
14
Wayne Burner Fuel Pressure Adjustment:
To adjust fuel pressure, First install a pressure gage
into the port just after the pump fuel exit. Turn the ad-
justing screw (located at the regulator port) clockwise
to increase, and counterclockwise to decrease. Do not
exceed 205 psi or lower the pressure below 130 PSI,
when checked at the post-pump pressure port.
The fuel pressure may need to be adjusted due to
altitude. For every 500 ft altitude above sea level, the
boiling point of water goes down 1 °F. At high altitude
environments, this boiling point change may require
the heat input to be lowered so the water input does
not turn to steam earlier than at the factory settings
and activate the pressure sensors and pressure relief
equipment when the unit is operated and much higher
altitudes from factory settings or local dealer site set-
tings. Check with your dealer before making local site
fuel pressure adjustments.
Also, as ambient temperature changes seasonally, the
fuel temperature in the feed tank and air temperature
inlet can impact fuel flow. In more extreme temperatures,
this local-site adjustment may also require different fuel
nozzles for fuel inlet temperatures that are at seasonal
extremes (higher or lower) in locations where the tem-
perature changes are beyond moderate temperatures
of between 40°F and 90°F. Colder temperatures will
make for a thicker flow and less fine a fuel spray while
hotter temperatures will make for a thinner flow a more
fine spray with the same nozzle. Consider alternate
nozzle configurations from the baseline factory-supplied
nozzle for operating in such temperature extremes if
performance is not meeting needs with air band and
fuel pressure settings alone.
NOTE:
When changing fuel pump, a by-pass plug must
be installed in return line port or fuel pump will not prime.
Removal of Soot and Heating Coil:
In the heating process, fuel residue in the form of soot
deposits may develop on the heating coil and block air
flow which will affect burner combustion. When soot
has been detected on visual observation, the soot
on the coil must be washed off after following the coil
removal steps.
1. Remove the tank head assembly by lifting the tank
head off.
2. Remove the two pipe nipples and associated fit-
tings.
3. Lift the coil out of the outer wrap.
CAUTION: The coil weighs about 80 lbs. Use proper
lifting techniques.
4. Clean, repair and replace the coil by reversing the
above steps.
Coil Reinstallation:
Reinstall by reversing the above steps 4 through 1.
Final Note:
The 12 VDC burner systems can draw as much as 18
amps! For such burners to run properly, the battery and
engine charging system must be kept in good condition.
The engine must run at the correct RPM to adequately
charge the battery. It is equally important not to throttle
down the engine on models without batteries, since all
power to run the burner comes solely from the engine.
Do not throttle down the engine at anytime while the
machine is operating.
MAINTENANCE
KNA Burner Air Adjustment
Reference Numbers
Air Band Locking Screws
Air Band
CAUTION: If white smoke appears from burner ex-
haust vent during start-up or operation, discontinue
use and readjust air bands.
NOTE: If a flue is installed, have a professional service-
man adjust your burner for a #1 or #2 smoke spot on
the Bacharach scale.
Karcher Clear Fire Oil Burner
Burner Air Adjustment: The oil burner on this machine
is preset for operation at altitudes below 1000 feet. If
operated at higher altitudes, it may be necessary to
adjust the air band for a #1 or #2 smoke spot on the
Bacharach scale.
To adjust, start machine and turn burner ON. Loosen
two locking screws found on the air band and close air
band until black smoke appears from burner exhaust
vent. Note air band position. Next, slowly open the air
band until white smoke just starts to appear. Turn air
band halfway back to the previously noted position.
Tighten locking screws.
