ESS GPS-5 User manual

Owner’s Manual
ESS Model GPS-5
Electrostatic
Spraying Systems
Owner’s Manual
ESS Model GPS-5

OWNER’S MANUAL
GPS5
Electrostatic Spraying Systems, Inc.
62 Morrison St. · Watkinsville, GA 30677-2749
CE certication applied for
Copyright © 2008, Electrostatic Spraying Systems, Inc. – All Rights Reserved
This manual last updated May 28, 2014

i
ESS GPS-5 OWNER’S MANUAL
CONGRATULATIONS!
You have just purchased one of the most advanced spraying systems
on the market today. Electrostatic Spraying Systems, Inc.1(ESS) is
committed to providing you with powerful spraying systems that are
easy to operate and maintain.
The products of ESS are the result of the eorts and creativity of many
people. In addition to input from engineering, marketing and manufac-
turing personnel, suggestions from our customers have been imple-
mented into the design of our equipment. We would like to hear your
ideas also! If you have any suggestions or comments regarding the
products or service of ESS write or call us at:
Electrostatic Spraying Systems, Inc.
62 Morrison St.
Watkinsville, Georgia 30677-2749
Phone: [phone]
1-800-213-0518
Fax: [phone]
[e-mail]
Please take time to read this manual before operating your new ESS
GPS-5™ sprayer. The manual contains important instructions for the
safe operation of this equipment. It also includes helpful suggestions
to maximize productive use of the GPS-5 sprayer. Essential cleaning
instructions should be followed to maintain your sprayer at peak ef-
ciency. Please carefully read and follow all instructions for your own
safety and the safety of others around you.
Thank you!
We appreciate your business and are proud that you have selected an
ESS sprayer for your operation.
Your new sprayer has been thoroughly tested and calibrated at the
factory. If you have any problems with it, please get in touch with us
immediately. We will be glad to answer any questions you have con-
cerning our equipment or service. ESS intends to support its customers
with ecient, helpful and friendly service. We appreciate your business
and sincerely hope that Electrostatic Spraying Systems, Inc. can meet
your present and future spraying equipment needs.
1 ESS GPS-5 Sprayer™, GPS-5™, MaxCharge™, and the ESS logo are copyrights or registered
trademarks of Electrostatic Spraying Systems, Inc.
A Kaibab Industries Company
For your personal records
Please record the model
and serial numbers of your
new sprayer here.
GPS-5
______________________
Model #
______________________
Serial #
______________________
Spray gun serial number
______________________
Date of purchase.
We encourage you to make copies of the“Spray Gun Yearly Service”
form in the back of this manual. Use this form every year you
send your gun in for maintenance and when we service the gun,
your warranty will renew for another year. The service will replace
the nozzle base, replace air and liquid hoses inside gun housing,
replace lters, and recalibrate the gun and thoroughly cleaning the
entire spray gun.

ii
ESS GPS-5 OWNER’S MANUAL

iii
ESS GPS-5 OWNER’S MANUAL
TABLE OF CONTENTS
Overview of the ESS GPS-5 Air-assisted Electrostatic Sprayer ............ 1
Safe operation of the GPS-5 Sprayer ............................................................ 2
Operator’s responsibility........................................................................... 2
Safety precautions ...................................................................................... 2
Chemical safety precautions................................................................... 2
About the low-voltage system of the MaxCharge spray gun ............. 3
Safety decals ......................................................................................................... 4
Features of the GPS-5 sprayer......................................................................... 5
Technical specications ............................................................................ 5
Operating Instructions ...................................................................................... 6
Unpacking and assembling the sprayer ............................................. 6
Before use....................................................................................................... 7
Steps for operation ..................................................................................... 8
After spraying ............................................................................................... 9
GPS-5 maintenance schedule.......................................................................10
REFERENCE SECTION
Engine....................................................................................................................11
Compressor .........................................................................................................12
Compressor air lter .................................................................................12
Tank pressure regulator ..................................................................................13
Pop-o valve .......................................................................................................13
Tongue handle ...................................................................................................13
Hose reel and liquid inlet lter .....................................................................14
Stainless steel tank............................................................................................15
Quick connects...................................................................................................16
How to store the hose quick-connects when not in use ....................17
Spray gun .............................................................................................................18
Air lter..........................................................................................................18
Trigger ...........................................................................................................19
Liquid lter assembly...............................................................................20
Nozzle assembly ........................................................................................21
Pre-spray check..................................................................................................22
Post-spray check................................................................................................22
Batteries................................................................................................................23
Yearly spray gun service..................................................................................24
Spraying with your ESS sprayer....................................................................25
Preparing a tank mix ........................................................................................26
Chemical compatibility ...................................................................................27
A note about operating temperatures ......................................................27
Trouble-shooting Guide .................................................................................29
GPS-5 spray gun service parts (drawing)..................................................30
GPS-5 spray gun service parts (key)............................................................31
Flow disk chart ...................................................................................................31
GPS-5 exploded view (drawing)...................................................................32
GPS-5 service parts...........................................................................................33
Warranty ...............................................................................................................35
Warranty card............................................................................................35a
Spray gun repair/Yearly service return form............................................37
Spraying with the GPS-5.

iv
ESS GPS-5 OWNER’S MANUAL

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ESS GPS-5 OWNER’S MANUAL
Overview of the ESS GPS-5
Air-assisted Electrostatic Sprayer
Air-assisted electrostatic sprayers produce electrically charged spray
drops that are carried to the plant canopy in a low pressure, gentle, air
stream. The heart of the GPS-5 is the patented MaxCharge™ nozzle.
Air and liquid enter separately at the rear of the nozzle. Just before
leaving the nozzle, the air hits the liquid stream to make many thou-
sands of tiny spray droplets that pass through the charging ring. An
electrical charge is applied to the spray droplets by the charging ring.
Then the charged spray droplets are blown out of the nozzle and
move into the plant canopy where they are attracted to plant material
by electrostatic forces. The electrostatic charge induced by the Max-
Charge™ nozzle is strong enough to allow the droplets to move in any
direction to cover all plant surfaces, even defying gravity to coat the
underside of leaves and the back side of fruits and vegetables. The re-
sult is uniform spray coverage on hidden areas deep inside of the plant
canopy where other sprayers miss.
The MaxCharge™ nozzle is easy to clean and corrosion-proof. The inte-
rior ceramic outlet resists wear three times better than stainless steel
outlets. These features combine to give the best spray coverage on the
market. This quality product is virtually maintenance-free, and assures
you of savings in the application of chemical.
The comparison of air-assisted electrostatic spraying versus conven-
tional spraying is dramatic. Electrostatically charged droplets are
attracted to plant surfaces.
Where Does the Spray Go?
The University of California completed a series of tests to investi-
gate what happens to spray liquid after it leaves the nozzle.
Conclusion: ESS technology places over 4 times the amount of
spray onto the plant surface using ½ the amount of chemicals.
Furthermore, they also reported that ESS sprayers send ⁄ less
chemicals to the ground and into the air. Less chemical used
overall, less waste and less drift than conventional equipment.
Imagine the environmental benet!

2
ESS GPS-5 OWNER’S MANUAL
OPERATOR’S RESPONSIBILITY
Read the Owner’s Manual.
It is the responsibility of the user to read the Owner’s Manual, to understand the
safe and correct operating procedures which pertain to the operation of the prod-
uct, and to maintain the product according to the Owner’s Manual. It is the owner’s
responsibility to ensure that all who are using this equipment read this manual.
The user is responsible for inspecting the equipment and for repairing and replacing
damaged or worn parts to prevent damage or excessive wear to other parts. It is the
user’s responsibility to deliver the machine for service or replacement of defective
parts which are covered by the standard warranty.
Lack of attention to safety can result in reduced eciency, accident, personal injury, or
death. Watch for safety hazards and correct deciencies promptly. Use the following safety
precautions as a guide when using this machine.
Safe operation of the GPS-5 Sprayer
Read the Owner's Manual. Failure to read the manual is considered a misuse of the equipment.
Use the GPS-5 sprayer ONLY for its intended use as described in this manual.
Before operating equipment, become familiar with all caution and warning decals axed to the sprayer.
Do not allow a child to operate the GPS-5 sprayer. Do not allow adults to operate the sprayer without
proper instruction.
Keep the area of operation clear of all persons and animals.
Do not apply chemicals when weather conditions favor drift from treated areas.
Turn o the sprayer when leaving it unattended.
Store sprayer in a dry place. Do not expose to freezing temperatures.
CHEMICAL SAFETY PRECAUTIONS
Read and follow all instructions on the chemical or pesticide manufacturer’s label.
Use protective clothing, eye protection and gloves when mixing chemicals and while spraying with
the GPS sprayer.
Always use a cartridge respirator, protective clothing and eye protection when spraying with the GPS-5.
Follow the chemical manufacturer’s recommendations in handling, mixing, applying, storing and
disposing of chemicals.
Be aware of decontamination methods in case a person, clothing, or equipment is accidentally
sprayed.
Be aware of poisoning symptoms and know the appropriate rst aid.
Know the length of time needed to pass before allowing people and pets to go back into the
sprayed area.
SAFETY PRECAUTIONS

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ESS GPS-5 OWNER’S MANUAL
About the low-voltage system of the MaxCharge™ spray gun
For operator safety, the MaxCharge spray gun is powered by a low-
voltage power supply. The rechargeable 9-volt batteries are in the
handle of the GPS-5 spray gun. The electrostatic charge imparted to
the spray is not strong enough to harm people. Some people report
feeling a“tingle” or a slight stinging sensation when the spray from the
nozzle falls on their bare skin.
Location of 9-volt rechargeable
battery pack in the handle of the
spray gun.
9v
Some owners report that they sometimes get a static shock when
spraying in an enclosed area. ESS wants to emphasize that these static
shocks, although sometimes unpleasant, are not at all dangerous to
people. They are simply an unfortunate consequence of spraying with
an electrostatic sprayer in an enclosed area. When you spray charged
particles onto other objects, some of the charge gets on you, or else
an opposite charge may be drawn up from the ground, depending on
the circumstances.
Here are some things to do to minimize static discharges. First make
sure that the sprayer is properly grounded. Your sprayer has a short
chain attached to the bottom of its case. It is important that this chain
touch the oor during use. If the chain is broken or missing, replace it.
Try misting the oor of the greenhouse or room with plain water
before spraying.
Pay attention to the exact conditions in which the shocks happen.
You may nd that you can prevent them by keeping your nger on
the metal trigger of the sprayer, rather than just holding its plastic
body. If the shocks happen only when you subsequently touch a piece
of equipment, try touching a painted or plastic part of it before you
touch metal.
You could also try wearing a dierent type of shoe. Leather will con-
duct better than rubberized soles and may lessen the problem.
Avoid touching sensitive electronic equipment such as computers,
printers, or cell phones while spraying . A static discharge could dam-
age them.

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ESS GPS-5 OWNER’S MANUAL
Safety decals
Appropriate safety decals are placed on ESS equipment in order to
alert the operator to possible dangers. If decals are missing, please
contact ESS immediately for replacement decals.
¡PRECAUCIÓN!
WARNING!
AGRICULTURAL CHEMICALS CAN BE
DANGEROUS. IMPROPER SELECTION
OR USE CAN SERIOUSLY INJURE
PERSONS, ANIMALS, PLANTS, SOIL OR
OTHER PROPERTY.
BE SAFE:
·SELECT THE RIGHT CHEMICAL
FOR THE JOB.
·HANDLE IT WITH CARE.
·FOLLOW THE INSTRUCTIONS
ON THE CHEMICAL
MANUFACTURER’S LABEL.
LOS PRODUCTOS QUÍMICOS AGRÍCOLAS
PUEDEN SER PELIGROSOS. LA SELECCIÓN O EL
USO INAPROPIADOS PUEDEN LESIONAR
SERIAMENTE A LAS PERSONAS, LOS ANIMALES,
LAS PLANTAS, LA TIERRA U OTRA PROPIEDAD.
TENGA CUIDADO:
· SELECCIONE EL PRODUCTO QUÍMICO
CORRECTO PARA EL TRABAJO.
· MANÉJELO CON CUIDADO.
· SIGA LAS INSTRUCCIONES DE LA ETIQUETA
DEL FABRIC ANTE DEL PRODUCTO
QUÍMICO.
READ AND FOLLOW THE CHEMICAL
MANUFACTURER’S INSTRUCTIONS
CAREFULLY.
It is extremely important for the owner/
operator’s safety as well as the safety
of other people in the vicinity that all
chemical safety precautions are fol-
lowed.
DANGER!
MOVING PARTS CAN
CRUSH AND CUT
Do NOT operate with
guard removed.
Do NOT place hands
or fingers under guard.
MANTÉNGASE
ALEJADO
Zona de protección para
evitar riesgos. No opere
este equipo sin todas sus
protecciones instaladas.
¡PELIGRO! DO NOT RUN THE SPRAYER WITHOUT
ALL GUARDS IN PLACE.
Serious injury can result.
This decal is located on the belt guard.
Do not operate your sprayer without
this guard in place. If the decal is miss-
ing, please contact ESS immediately for
a replacement decal.
·DO NOT REMOVE TANK LID OR
RELEASE TANK PRESSURE WHILE
COMPRESSOR IS RUNNING.
·RELEASE TANK PRESSURE BEFORE
REMOVING LID OR TANK HOSE
CONNECTIONS.
·KEEP FACE AWAY WHEN RELEASING
PRESSURE AND WHILE REMOVING
TANK LID.
·DO NOT OVERFILL TANK.
·FILL TO 4 INCHES (10 CM) FROM TOP
OF TANK WHEN USING TANK
AGITATOR SYSTEM.
·NO RETIRE LA TAPA DEL TANQUE NI LIBERE LA
PRESIÓN DEL TANQUE MIENTRAS LA COMPRE
SORA ESTÉ FUNCIONANDO.
·LIBERE LA PRESIÓN DEL TANQUE ANTES DE
RETIRAR LA TAPA O LAS CONEXIONES DE LA
MANGUERA DEL TANQUE.
·MANTENGA EL ROSTRO ALEJADO CUANDO LIBERE
LA PRESIÓN Y MIENTRAS RETIRA LA TAPA DEL
TANQUE.
·NO SOBRELLENE EL TANQUE.
·LLÉNELO HASTA 10 CENTÍMETROS (4 PULGADAS)
DE LA PARTE SUPERIOR DEL TANQUE CUANDO
USE EL SISTEMA AGITADOR DEL TANQUE.
¡PRECAUCIÓN!
WARNING!
CAUTION:
The stainless steel tank
operates under pressure.
This decal describes important informa-
tion on correct use of the tank and its
agitator.
CLEAN
FILTER
REGULARLY
REMEMBER TO DISASSEMBLE AND CLEAN
THE FILTERS REGULARLY.
The performance of your GPS sprayer
can suer if the lters are not kept clean.
This label is placed on the charger of all
sprayguns.

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ESS GPS-5 OWNER’S MANUAL
Features of the GPS-5 Sprayer
MaxCharge™ Spray gun
Self-contained — does not
need an external air supply
6.5 hp Briggs & Stratton
gasoline engine
All-metal frame features durable welded
construction and powder-coated nish
About your GPS-5 sprayer
The GPS-5™ is a self-contained
unit. The engine provides
power to the compressor to
produce pressurized air. This
air passes through the radia-
tor, is cooled, and follows two
dierent routes from a black
iron tee. One route goes to the
hose reel and in the red hose
of the twin-line hose. The other
route goes to the tank pressure
regulator and then to the tank.
When the engine is on and the
tank pressure regulator is set
between 12-15 PSI, the tank is
continuously pressurized and
agitated to prevent separation
and settling of the chemical.
From the tank, the line goes to
the hose reel and in the gray
hose of the twin-line hose. The
twin-line hose, which carries
pressurized liquid and air lines
feeds into the spray gun. The
liquid combines with the pres-
surized air and atomizes into
40 micron VMD (volume mean
diameter) drops. The droplets
are electrostatically charged
and sprayed from the nozzle
assembly. Due to the electro-
static charge, the droplets are
attracted to all plant surfaces in
the direction that the handgun
points, including the back of
leaves and foliage deep within
the canopy.
Can be pulled by hand or
towed with small vehicle
47.5 meter (150 feet)
twin-line hose
18.9 liter (5-gallon)
Stainless-Steel tank
Heavy-duty wheels
Nozzles 1
External air supply required No
Electricity required No
Standard hose length 150 ft. (45.7 m.)
Weight empty 230 lbs. (104.3 kg.)
Weight full 270 lbs. (122.5 kg.)
Shipping weight 350 lbs. (158.8 kg.)
Main tank capacity 5 gal. (18.9 L.)
Air line pressure 50 to 60 PSI
(3.5 kg./cmto 4.2 kg./cm)
Dimensions 40”H × 22”W × 42”L
(1 m. × 0.6m. × 1.1m.)
Tank Pressure 12 – 15 PSI
(0.8 – 1.1 kg./cm2)
Flow rate 4 gal./hr. (15.1 L../hr.)
Drop size 40 microns
Spray range 15 to 20 ft.
(4.6 m. to 6.1 m.)
Available options 250 ft. (76.2 m.) hose
2 or 3-headed spray guns
Technical specications
Designed for the needs of larger commercial greenhouses
and coee growers
Compatible with all conventional chemicals and fungicides
Spray up to 40,000 sq. ft. per hour

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ESS GPS-5 OWNER’S MANUAL
Operating instructions
ALL OPERATORS must read this Owner’s Manual completely
and thoroughly before operating the GPS-5 sprayer. They
must be familiar with all operating instructions and safety
precautions.
Unpacking and assembling the sprayer
In the shipping box there should be:
one GPS-5 sprayer
one spray gun in a box,
one handle,
four wheels, and
one GPS-5 Parts Kit.
The sprayer is fastened to the shipping pallet with cable ties. Cut the
ties to remove the sprayer. The GPS wagon has had its handle and
wheels removed for shipping. To prepare the cart for operation, fasten
the handles and wheels onto the wagon.
Carefully open the spray gun box, remove the spray gun, and unwrap
the bubble wrap from the spray gun. Store the box and bubble wrap
for future shipping. You will need this box to return the spray gun for
its Yearly Service.
The Parts Kit contains a collection of small parts commonly needed to
maintain and repair your GPS-5 sprayer as well as the battery charger
for the spray gun, a spray gun shoulder pad, and the GPS-5 Owner’s
Manual. Please store your Parts Kit in a safe place for future use.
Among the items in the Parts Kit you will nd one extra ow disk and
one extra strainer. We call your attention to these parts because they
are indeed very small and easy to overlook; however they are essential
for your sprayer to run correctly. (See the section about the air lter
for detailed instructions on cleaning and replacing the air lter. See
the section on the liquid lter to clean or replace the ow disk and the
strainer.)
A warranty registration card is bound into the manual after the
Warranty page. After unpacking the sprayer, please take time to ll this
card out and send it in to ESS. This will insure your warranty protection
in the event anything happens to your sprayer or handgun.
The hardware to reattach the handle
and wheels is in your Parts Kit box.

7
ESS GPS-5 OWNER’S MANUAL
Before use
The engine and the air compressor have been lled with the proper
lubricant at the factory. However, their lubricant levels must be
checked before the GPS-5 is operated. If they need to be replenished,
use 30 weight compressor oil in the compressor and 10W-30 oil in the
engine. Fill the gasoline engine tank with unleaded gasoline.
Please consult the Briggs and Stratton
gasoline engine manual for detailed
instructions on operating and
maintaining of the engine.
The Tank Pressure Regulator
controls the pressure in the
tank. Set the tank pressure to
12-15 PSI.
Check the compressor
oil level before each
spray application.
Visually check the gasoline tank fuel
level before each spray application.
Check the engine
oil level before each
spray application.
To check the engine oil level, unscrew the yellow
plastic plug. Oil level should be up to the lip of the
ll hole.
To check the compressor oil, remove the 7/16”
plug. Oil level should be up to the lip of the hole.

8
ESS GPS-5 OWNER’S MANUAL
Engine/Compressor
Pre-spray check
Steps for operation
1. Check oil level in engine; add oil if needed
2. Check gas level in engine tank; add gas if needed
3. Check oil level in compressor; add oil if needed
4. Prepare the tank mix. Open tank. Pour mix in. Close tank
5. To start the engine, Turn the engine ON. Set the Run/Choke
Control to CHOKE (far right) and the Engine Speed Control
to FAST (to the right) before pulling the starter cord. After
the engine engages, move the Run/Choke control to Run
(towards the left).
6. Set the tank pressure to 12-15 PSI.
7. Connect the air line hose to the air connection from the
compressor to air leader on the spray gun.
8. Connect the liquid line hose from the tank to the liquid
leader on the spray gun.
9. Aim spray gun and engage the trigger; lock trigger if
desired. Spray with even, sweeping strokes.
NOTE: It may take about a few moments for air to clear
the lines before liquid sprays regularly without air bubbles.
To set the tank pressure:
Start engine. Pull the adjustment knob’s black plastic cover to un-
lock it. Turn left (counter-clockwise) to decrease pressure; turn right
(clockwise) to increase pressure. Set the pressure between 12 to 15 PSI
(marked in light green). Push the black plastic cover in to lock the new
setting.
The Tank Quick Connects con-
nect the tank to the incoming
airline and outgoing liquid line.
The Spray Gun Quick Connect Plugs attach to the
Spray Gun Quick Connect Sockets.

9
ESS GPS-5 OWNER’S MANUAL
After spraying:
1. Disengage trigger.
2. Turn engine o.
3. Open stainless steel tank; clean its interior and exterior;
ll tank with 5 liters (1.25) gallons of clean water; close tank
4. Disconnect air and liquid spray gun quick connects.
5. Disassemble liquid lter assembly; set aside.
6. Put liquid quick connect plug (which is still threaded in
1/8 inch NPT body) into liquid quick connect socket;
water will begin to run out of quick connect plug;
allow 4 liters (1 gallon) to run through to clean lines.
7. Unplug liquid quick connect plug from liquid quick connect
socket to stop ow of liquid.
8. Clean liquid lter assembly.
9. Reassemble liquid lter assembly.
10. Reconnect quick connects.
11. Turn engine on.
12. Engage trigger and allow remaining liter (approximately
1 quart) of water to run through to clean spray gun; allow
air to ow for 30 seconds more to reduce possibility of
corrosion.
13. Turn engine o.
14. Disconnect spray gun quick connects.
15. Disconnect the air hose from the air compressor.
16. Apply silicone spray or similar lubricating oil to all
quick connects.
17 Clean the nozzle assembly.
18. Check compressor air lter; clean if needed.
Sil-Glyde is an excellent silicone-based
protective lubricant. You may purchase
it directly from ESS. S/N # 3174

10
ESS GPS-5 OWNER’S MANUAL
GPS-5 maintenance schedule
Check engine oil level and add oil as needed Before every spray application
Check compressor oil level and add oil as needed Before every spray application
Clean the liquid lter at hose reel and spray gun After every spray application
Clean the nozzle When spray pattern is dierent than when the
GPS-5™/GPS-5™ was new
Recharge batteries in spray gun When charging indicator does not light during
operation (about every 8 operational hours)**
Replace batteries in spray gun When batteries no longer hold a sucient
charge to complete a ten-hour work session
or show other signs of battery deterioration
Service air cleaner cartridge in engine Every 25 operational hours OR every season**
Change engine oil After rst 5 operational hours, then every
50 operational hours OR every season**
Clean and replace air lter in compressor Every 75 operational hours OR if dirty**
Clean spark plug in engine Every 100 operational hours OR every season**
Change compressor oil Every 100 operational hours OR if dirty**
Check and tighten bolts Every month
Check compressor air intake lter; clean as needed After every spray application
Please observe the recommended maintenance schedule for your GPS-5 sprayer in order to preserve
spray quality and the working life of the unit. If you use heavy wettable powders to spray or if you operate
the GPS-5 in a dusty environment, you may need to clean liquid and air lters more often than these rec-
ommendations. Visually inspect the nozzle and trigger assembly often and clean as necessary.
** Whichever comes rst

11
ESS GPS-5 OWNER’S MANUAL
REFERENCE SECTION
Engine
The GPS-5™ uses a 6.5 horsepower Briggs & Stratton gasoline engine
to power the air compressor. Before each spray operation, the gas and
oil levels should be checked. Use lead-free gasoline and 10W-30 de-
tergent oil. Follow the Maintenance Schedule on page 9 for periodic
engine maintenance procedures.
To start engine:
1. Turn ON.
2. Set the Engine Choke control to Choke (to the far right).
2. Set the Throttle Speed control to Fast (to the far right;
indicated by a rabbit icon.).
3. Pull the starter cord.
4. After the engine engages, move the Engine Choke control to
run (far left).
To stop engine:
1. Move Throttle Speed control towards the turtle icon (slow)
at the left.
2. Turn ON/OFF switch to OFF.
Note: Do not use choke to stop engine, as a backre or engine damage
may result.
Manifold & Shield
CAUTION HOT
Gasoline ll cap
Oil ll/Oil check
(visible from
other side)
Engine Choke
control
Pull cord
Throttle
Speed control
ON/OFF switch
Oil drain

12
ESS GPS-5 OWNER’S MANUAL
Compressor
The compressor produces pressurized air which is used to atomize and
propel the liquid spray. The oil level should be checked before each
spray application. Use only 30-weight compressor oil in the compres-
sor. Follow the Maintenance Schedule on page 10 for periodic engine
maintenance procedures.
NOTE:
The GPS-5 engine and compressor
become hot during normal use.
To check the compressor oil, remove the 7/16” oil ll plug. Oil level
should be up to the lip of the hole.
Compressor air lter
The compressor has an air intake lter located on the front side of the
compressor. This lter should be checked regularly. If it gets clogged,
it will cause the compressor to overheat. Take note of the conditions
you are spraying in. The lter will need to be cleaned more often if it’s
dusty.
HOT
DANGER
Location of the compressor air intake
lter.
To clean the compressor air lter:
Make sure the compressor has cooled down.
Remove lter from the compressor.
Use compressed air to clean the lter, blowing from the inside
surface to the outside.
Replace the lter in its holder, felt side in.
When the lter can no longer be cleaned eectively with compressed
air, replace it. A spare lter is in your parts kit..
The replacement compressor air lter is available from ESS. Order
S/N #4218.
Cleaning the compressor air lter with
compressed air.

13
ESS GPS-5 OWNER’S MANUAL
Pop-off valve
The GPS-5™ has a 100 PSI spring-loaded pop-o valve which is con-
nected to the tank pressure regulator. The valve relieves pressure
greater than 100 PSI to protect the sprayer from being damaged by
extreme air pressure.
If the pop-o valve blows, shut o the sprayer immediately. Deter-
mine the cause of the out-of-range air pressure and repair. Replace the
pop-o valve (ESS S/N 62).
Tank pressure regulator
The tank pressure regulator controls the amount of pressure in the
tank pressure line. Optimum tank pressure is 12-15 PSI.
To set the tank pressure:
Start engine. Pull the adjustment knob’s black plastic cover to un-
lock it. Turn left (counter-clockwise) to decrease pressure; turn right
(clockwise) to increase pressure. Set the pressure between 12 to 15 PSI
(marked in light green). Push the black plastic cover in to lock the new
setting.
Note: For best results, set the pressure from a lower pressure to a high-
er pressure. If the pressure is set too high, adjust the regulator below
the desired pressure then adjust it up to the desired pressure.
Tongue handle
The tongue handle can be pulled by hand or attached to a small mo-
torized vehicle for towing. In order to pull the sprayer, the vehicle
must have a hole on the back of its chassis frame for a pin. Place a pin
through the hole in the tongue handle and through the hole in the
vehicle to pull the sprayer.
Keep safety in mind and use common sense when towing the GPS-5.
Do not allow passengers to ride the GPS-5. Do not exceed a safe speed
for the conditions and terrain. Use caution on turns and sharp curves
as the sprayer may tip over.
NOTE: ESS will not be held responsible for accidents that
occur as a result of hazardous operations.

14
ESS GPS-5 OWNER’S MANUAL
The hose reel contains the twin line hose running from the main unit
to the handgun. Air (red hose) and liquid (gray hose) are plumbed into
the hose reel from the compressor and liquid tank. There is a lter
attached to the liquid inlet on the hose reel. The lter consists of a
strainer, O-ring (installed on cap) , and bowl-shaped cap. Periodically
check and clean this lter to clear any debris that accumulates there.
Replace the O-ring when it become worn.
The cap turns counter-clockwise (to the left) to open and clockwise (to
the right) to close.
Hose reel and liquid inlet filter
Liquid inlet lter
How to tell the cap end of the strainer
It’s important to replace the strainer in the correct direction. Carefully
examine the ends of the strainer. If you can see the terminus of the inte-
rior plastic ribs, that’s the “open” end. If there is a smooth plastic ring, that
is the “closed” end. Place the closed end into the lter cap (Remember:
CLOSED to CAP).