620-622 • 9.800-187.0 • Rev. 9/10
OPERATOR’S MANUAL
PRESSURE WASHER
10
Fuel Control System:
These machines utilize a fuel solenoid valve located
on the fuel pump to control the flow of fuel to the
combustion chamber. This solenoid valve, which is nor-
mally closed, is activated by a flow switch when water is
flowing through it. When an operator releases the
trigger on the spray gun, the flow of water through the
flow switch stops, turning off the current to the fuel
solenoid. The solenoid then closes, shutting off the
supply of fuel to the combustion chamber. Controlling
the flow of fuel in this way allows for an instantaneous
burn or no burn situation, thereby eliminating high
and low water temperatures, and combustion smoke
normally associated with machines incorporating
a spray gun.
CAUTION: Periodic inspection is recommended to
insure that the fuel solenoid valve functions prop-
erly. This can be done by operating the machine and
checking to see that when the trigger on the spray gun
is in the off position, the burner is not firing.
Fuel Pressure Adjustment:
To adjust fuel pressure, turn the pressure adjusting
screw clockwise to increase, counterclockwise to
decrease. Do not exceed 200 psi.
NOTE: When changing fuel pump, a by-pass plug
must be installed in return line port or fuel pump will
not prime.
Air Adjustment:
Note: The oil burner on this machine is preset for op-
eration at altitudes below 1000 ft. If operated at higher
altitudes, it may be necessary to adjust the air band
setting. Adjust air band for a #1 or #2 smoke spot on
the Bacharach scale. A one-time initial correction for
your location will pay off in economy, performance,
and extended service life. If a smoky or eye-burning
exhaust is being emitted from the stack, two things
should be checked. First, check the fuel to be certain
that kerosene or No. 1 home heating fuel is being
used. Next, check the air adjustment on the burner.
An oily, smoky fire indicates a lack of air and the air
band should be moved to allow the air to flow through
the burner. Sharp eye-burning fumes indicate too
much air flowing through the combustion chamber.
The air band should be readjusted to allow less air
to flow through the burner.
To adjust Beckett burner: Start machine and turn
burner ON. Loosen two locking screws found in the
air shutter openings (refer to illustration) and close
air shutter until black smoke appears from burner
exhaust vent. Note air band position. Next, slowly open
the air shutter until white smoke just starts to appear.
Turn air shutter halfway back to the black smoke posi-
tion previously noted. Tighten locking screws.
If the desired position cannot be obained using only
the air shutter, lock the air shutter in as close a position
as can be obtained, then repeat the above procedure
on the air band setting.
Burner Nozzle:
Keep the tip free of surface deposits by wiping it with
a clean, solvent-saturated cloth, being careful not to
plug or enlarge the nozzle. For maximum efficiency,
replace the nozzle each season.
Rupture Disk:
If pressure from pump or thermal expansion should
exceed safe limits, the rupture disk will burst, allowing
high pressure to be discharged through hose to ground.
When disk ruptures it will need to be replaced.
Cleaning of Coils:
In alkaline water areas, lime deposits can accumulate
rapidly inside the coil pipes. This growth is increased
by the extreme heat build up in the coil. The best
preventative for liming conditions is to use high quality
cleaning detergents. In areas where alkaline water is
an extreme problem, periodic use of Deliming Powder
(Part #98040590) will remove lime and other deposits
before coil becomes plugged.
PREVENTATIVE MAINTENANCE & SERVICE
Air Band
Adjustment
Screw
Air Band
Fuel
Pump
