Briggs & Stratton CE8070 User manual

Familiarization & Troubleshooting Guide
PRESSURE WASHER
BRIGGS & STRATTON CORPORATION
Milwaukee, WI 53201
Part No. B3277GS Rev. 0 11/98
Printed in U.S.A.
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& Troubleshooting Guide
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Pressure Washer
Familiarization & Troubleshooting
Guide
Electronic Version #B3277 Rev. 1 4/03
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This guide has been written and published by Briggs & Stratton Corporation to aid our dealers' mechanics and
company service personnel when servicing the products described herein.
It is assumed that these personnel are familiar with the servicing procedures for these products, or like or similar
products, manufactured by Briggs & Stratton Corporation. It is also assumed that they have been trained in the
recommended servicing procedures for these products, which includes the use of mechanics hand tools and any
special tools that might be required.
Proper service and repair is important to the safe, economical and reliable operation of all engine driven systems.
The troubleshooting, testing, service and repair procedures described in this guide are effective methods of
performing such operations.
We could not possibly know of and advise the service trade of all conceivable procedures or methods by which a
service might be performed, nor of any possible hazards and/or results of each procedure or method. We have
not undertaken any such wide evaluation. Therefore, anyone who uses a procedure or method not described by
the manufacturer must first satisfy himself that neither his safety, nor the safety of the product, will be
endangered by the service or operating procedure selected.
All information, illustrations, and specifications contained in this guide are based on the latest production
information available at the time of publication. However, Briggs & Stratton Corporation reserves the right to
change, alter, or otherwise improve the product at any time without prior notice.
Some components or assemblies of the product described in this guide may not be considered repairable.
Disassembly, repair and reassembly of such components may not be included in this guide.
Copyright © 2003 Briggs & Stratton Corporation
All rights reserved.
No part of this material may be reproduced or transmitted, in any form or by any means, electronic or
mechanical, including photocopying, recording or by any information storage and retrieval system, without prior
permission in writing from Briggs & Stratton Corporation.

1
1 • Operation 5
2 • Pressure Washer Components 7
Power Source 7
Pressure washer pumps 7
Inlet and Outlet Check Valves 8
Unloader - Pressure Regulator 8
Thermal Bypass System 9
Chemical Injection 9
Easy Start Valve 10
High Pressure Hose 11
Spray Guns 11
Spray Wands and Nozzles 12
3 • General Information 13
Part 1 - General Maintenance 13
Chemical Injection System 13
Inlet Water Supply Connector 13
Inlet Supply Filter/Strainer 13
Hose, Spray Gun and Wand Systems 13
Spray Nozzle Servicing 14
Part 2 - Lubrication 15
Check Pump Oil Level 15
Change Pump Oil 15
Part 3 - Storage 16
Pump Storage 16
Protection Against Freezing 16
Purging Air From the System 16
4 • Small Frame Electric Pump 17
Part 1 - Specifications and Views 17
Performance Specifications 17
Cross-Sectional View 18
Exploded View 20
Part 2 - Disassembly 22
General Information & Special Tools 22
Pump Head 22
Piston Housing Removal 23
Piston Housing Disassembly 24
Chemical Injection System 24
Auto Start Switch Assembly 25
Axial Cam 26
Part 3 - Inspection 27
Seals, O-Rings, and Gaskets 27
Piston & Spring Assemblies 27
Pump Head and Piston Housing 27
Axial Cam Drive Components 28
Part 4 - Reassembly 29
Pump Head Assembly 29
Auto Start Switch Assembly 29
Chemical Inject Assembly 30
Piston Housing Assembly 31
Pilot Spacer Installation 31
Pump Head Bolts 32
Assemble Axial Cam 32
Oil Fill 32
Main Component Assembly 32
Final Assembly and Test 33
Part 5 - Troubleshooting 34
TABLE OF CONTENTS
Table of Contents
Portable Pressure Washer Familiarization and Troubleshooting Guide

Small Frame Gas Pump 35
Part 1 - Specifications and Views 35
Performance Specifications 35
Cross-Sectional view 36
Exploded View 38
Part 2 - Disassembly 40
General Information & Special Tools 40
Pump Head 40
Piston & Unloader Housing Removal 40
Piston & Unloader Housing Disassembly 41
Chemical Injection System 42
Unloader 42
Engine Adapter 43
Part 3 - Inspection 43
Seals, O-Rings, and Gaskets 43
Piston & Spring Assemblies 43
Engine Adapter, Pump Head and
Piston/Unloader Housing 44
Axial Cam Drive Components 44
Part 4 - Reassembly 45
Engine Adapter 45
Unloader Assembly 45
Chemical Injection Assembly 45
Piston & Unloader Housing Assembly 46
Pump Head Assembly 46
Main Component Assembly 47
Pilot Spacer Installation 48
Pump Head Bolts 49
Oil Fill 49
Part 5 - Troubleshooting 50
5 • Medium Frame Pump 51
Part 1 - Specifications and Views 51
Performance Specifications 51
Cross-Sectional View 52
Exploded View 55
Part 2 - Disassembly 56
General Information & Special Tools 56
Pump Head 56
Axial Cam Drive Components 57
Pistons and Piston Springs 57
Pump Head 58
Spacer Plate 58
Inlet Check Valves 59
Outlet Check Valves 59
Unloader Spindle Assembly 59
Chemical Injection System 60
Thermal Bypass Actuator Removal 60
Part 3 - Inspection 61
Seals, O-Rings, and Gaskets 61
Seals 61
Check Valves 61
Head Gasket 61
Engine Adapter O-Rings 62
Engine Adapter, Pump Crankcase and
Spacer Plate/Head 62
Axial Cam Drive Components 62
Piston & Spring Assemblies 62
High Pressure Outlet/Chemical
Injection Assembly 63
Part 4 - Reassembly 64
Engine Adapter 64
Piston Oil Seals and Pistons 65
Spacer Plate 67
High Pressure Seal Assembly 67
Check Valve Assembly 68
High Pressure Outlet and Chemical
Injection Assembly 69
Unloader Spindle Assembly 69
Pump Head Installation 70
Main Component Assembly 71
Oil Fill 72
Part 5 - Troubleshooting 73
2
Table of Contents
Portable Pressure Washer Familiarization and Troubleshooting Guide
TABLE OF CONTENTS

3
6 • Large Frame Pump 75
Part 1 - Specifications and Views 75
Performance Specifications 75
Cross-Sectional View 76
Exploded View 78
Part 2 - Disassembly 80
General Information & Special Tools 80
Pump Head 80
Axial Cam Drive Components
(Tapered Engine Shaft) 81
Axial Cam Drive Component
(Straight Engine Shaft) 82
Pistons and Piston Springs 82
Regulator/Unloader Valve 82
Cylinder Head 84
Thermal Bypass Actuator Removal 85
Spacer Plate 86
Part 3 - Inspection 87
Seals, O-Rings, and Gaskets 87
Oil Seals 87
Inlet Check Valve Seals 87
Outlet Check Valve Seals 87
Head Gasket 88
Engine Adapter Gasket 88
Engine Adapter, Pump Crankcase,
Spacer Plate and Head 88
Axial Cam Drive Components 88
Piston & Spring Assemblies 89
Unloader-Pressure Regulator Valve 90
Part 4 - Reassembly 91
Engine Adapter 91
Piston Oil Seals and Pistons 94
Spacer Plate 96
Pump Head Assembly 96
Pump Head Installation 98
Unloader-Pressure Regulator Valve 99
Main Component Assembly 99
Oil Fill 101
Part 5 - Troubleshooting 102
Glossary 105
TABLE OF CONTENTS
Table of Contents
Portable Pressure Washer Familiarization and Troubleshooting Guide

4
Table of Contents
Portable Pressure Washer Familiarization and Troubleshooting Guide

5
Operation of a pressure washer system may be briefly
described as follows. Please refer to Figure 1.1 for visual
component identification:
1. An inlet hose delivers water to the motor-driven, piston-
type pump. An inlet strainer (item 6) protects the pump
(item 5) against damage from solid impurities. The motor
driving the pump (item 9) may be gas or electric.
2. Rotary motion of the motor crankshaft is converted to
reciprocating motion of the pump’s pistons using an axial
cam.
On a piston’s ‘suction’ stroke, an inlet valve opens and
water is drawn into the piston chamber. On the piston’s
‘pressure’ stroke, that piston’s inlet check valve closes and
its outlet check valve is forced open so pressurized water
can leave the chamber. There is one inlet check valve and
one outlet check valve for each piston.
PRESSURE WASHER OPERATION
Section 1 • Operation
Pressure Washer Familiarization and Troubleshooting Guide
Item Name
1 Spray nozzle
2 Hi-Lo nozzle collar
3 Spray gun extension wand
4 Spray gun with locking trigger
5 Pump, including optional thermal relief and/or
easy start valve
Item Name
6 Inlet strainer
7 Unloader/pressure regulator valve
8 Chemical inject fitting (optional)
9 Engine on cart
10 High pressure hose
Figure 1.1 — Example Pressure Washer System

6
3. The linear movement of the pistons pump a fixed volume
of water through the pressure washer system. The
volume of water flow depends on
a. piston diameter
b. length of piston stroke
c. number of pistons
d. number of piston strokes per minute.
4. The pressure that builds up in the system then depends
on the size of the spray nozzle orifice (item 1).
5. The fixed volume of water flows past an
unloader/pressure regulator valve (item 7), an optional
chemical injection assembly (item 8), through a high-
pressure hose (item 10), and to a spray gun (item 4).
6. The spray gun permits the operator to turn the flow of
water on or off.
7. If the water flow is turned off, water pressure within the
pump will increase until the unloader/regulator valve
(item 7) is moved off its seat. Flow is then bypassed back
to the pump inlet through an internal bypass channel.
Fluid bypass continues as long as the spray is turned off.
8. Recirculating bypass water can become hot enough to
damage seals and other pump parts. Some pressure
washer systems may be equipped with an internal thermal
relief valve which automatically replaces hot water with
cool water.
9. The optional chemical injection assembly (item 8) permits
detergents or other chemicals to be drawn into the water
stream and (along with the water) discharged from the
nozzle.
10. The nozzle collar (item 2), a part of the spray gun
nozzle, permits easy selection of high or low velocity
spray or a fan or stream spray pattern.
11. An optional easy start valve relieves pump outlet
pressure during cranking for quicker and easier starts.
12. As a nozzle is used, it often becomes clogged with
various types of matter. A clogged nozzle obstructs the
water flow causing a reduction in outlet pressure. It also
may cause the water stream to pulsate while the gun is
triggered. Therefore, the nozzle should be checked and
cleaned before every use, using the cleaning kit provided
with every Generac Portable Products®
pressure washer system.
13. The flow of water through the nozzle will gradually wear
away the nozzle orifice, causing the orifice to become
larger. This enlargement will eventually cause a reduction
in system pressure. For this reason, the nozzle should be
replaced periodically and always replaced with the
correct nozzle.
Section 1 • Operation
Portable Pressure Washer Familiarization and Troubleshooting Guide

7
Power Source
Generac Portable Products® uses several
engine manufacturers and different pump types on its
pressure washers. Generac Portable Products®
also uses an electric motor on some models.
The motor horsepower rating is designed into the overall
rating of the pressure washer. Pressure pumps require a
specified amount of horsepower for the pressure rating of
the pump. It is important to remember that engine
performance may be miss-diagnosed as a failed pump, and a
failed pump may also be miss-diagnosed as a faulty engine.
This manual does not cover service and repair of the engine.
Refer to the engine manufacturers’ service manual for engine
repair specifications.
Pressure washer pumps
Generac Portable Products® pressure washer
pumps are positive displacement, piston type pumps. They
use an axial cam to impart a reciprocating motion to its
three (3) pistons. The volume of water moved by the pump
depends on:
1. The axial distance each piston moves on its pressure
stroke
2. The diameter of each piston bore
3. The rotating speed of the axial cam (RPM of the engine or
electric motor)
4. The number of pistons
Theoretically, a pump will always move the same volume of
water, regardless of flow restrictions.
The pump’s axial cam is coupled to the engine crankshaft, so
that it revolves at the same speed as the engine. Figure 2.1
depicts a simplified cross-sectional diagram of a typical
pressure washer pump mechanism.
If the pump simply discharges water to atmosphere, no
pressure will be created. A pressure buildup in the system
occurs when flow is restricted downstream from the pump.
By adding a nozzle to the system, pressure will increase to
force the same volume of water through the nozzle orifice.
The smaller the nozzle orifice, the greater the pressure
needed to force the pumped volume through the nozzle.
PRESSURE WASHER COMPONENTS
Section 2 • Pressure Washer Components
Portable Pressure Washer Familiarization and Troubleshooting Guide
Figure 2.1 — Pressure Washer Pump
Item Name
1 Pressure adjust knob
2 Thermal bypass actuator
3 Inlet check valve
4 Garden hose connector/strainer
5 Thermal bypass outlet
6 Axial cam
7 Engine drive shaft
8 Engine adapter bearing assembly
9 Piston shoe bearing assembly
10 Piston spring retainer
11 Piston return spring
12 Piston
13 Outlet check valve
14 High pressure discharge port

8
Inlet and Outlet Check Valves
A set of six (6) inlet and outlet check valves work in
conjunction with the pump pistons to create volume flow.
As a piston is moved toward the axial cam by its return
spring during its suction stroke, that piston’s inlet check
valve opens and allows water to enter the pumping
chamber. During the suction stroke, that piston’s outlet
check valve is forced closed, as depicted in Figure 2.2.
When the piston is pressed forward by the axial cam on its
pressure stroke, its inlet check valve is forced closed and its
outlet check valve is forced open, as seen in Figure 2.3.
Unloader - Pressure Regulator
Output water pressure can be adjusted using the pressure
adjust knob on the Unloader-Pressure Regulator assembly.
Turn the knob clockwise to increase pressure (up to the
rated maximum pump pressure), counterclockwise to
decrease pressure.
The pressure washer is provided with an unloader -
pressure regulator valve to protect the pump and hose
system whenever water flow is blocked upstream. Blockage
is caused when the spray gun trigger is normally closed or
by a kinked pressure hose or a clogged nozzle. Without an
unloader system, water pressure could increase until the
engine stalls or part of the system ruptures to relieve the
pressure.
As shown in Figure 2.4, the unloader valve will open at a
preset maximum pressure to divert all or part of the flow
back to the pump inlet. During such shutdown conditions,
the water will circulate from the pumping chambers to the
pump inlet and then back to the pumping chambers.
Section 2 • Pressure Washer Components
Portable Pressure Washer Familiarization and Troubleshooting Guide
Figure 2.4 — Typical Unloader - Pressure Regulator System
Figure 2.2 — Inlet Check Valve - Suction Stroke
Figure 2.3 — Outlet Check Valve - Pressure Stroke
Item Name
1 Inlet check valve
2 Outlet check valve

9
Thermal Bypass System
When the trigger on the gun is not squeezed, the water in
the pump is recirculating and under pressure. This condition
causes the water in the pump to become hot. Excessively
hot water may cause damage to the pressure washer pump
elements. To resolve this problem, some
Generac Portable Products® pressure washers
are equipped with a thermal bypass system. Figure 2.5
depicts components of such a system.
At a water temperature of approximately 140°F, the thermal
actuator stem will push the thermal piston off its seat.
Heated water will then bleed out of the pump to the
ground. As cool water enters the pump, the thermal
actuator stem retracts and the thermal piston closes against
its seat, halting the water bleed-off.
Chemical Injection
Generac Portable Products® pressure washers
commonly incorporate a means of adding wax or
cleaning/sanitizing chemicals into the low-pressure water
stream. As depicted in Figure 2.6, the chemical injection
assembly includes a venturi, a spring-loaded ball and seat, a
chemical siphon tube, and a strainer.
As low-pressure water flows through the injector venturi
throat, its velocity increases and its pressure decreases. The
suction created by the low pressure at the venturi throat
draws the liquid chemical through a strainer into the siphon
tube, around and past the spring-loaded ball, through small
orifices in the venturi, and into the water stream.
Chemical injection only operates at the low pressure setting
because detergents and chemicals require some soak or
residence time on the surface to be cleaned. Low pressure
also avoids splashing, over-spraying, and waste.
Section 2 • Pressure Washer Components
Portable Pressure Washer Familiarization and Troubleshooting Guide
Figure 2.5 — Thermal Bypass System
Item Name
1 Thermal bypass actuator
2 Thermal bypass actuator stem
3 O-ring
4 Thermal bypass piston
5 Thermal bypass spring
Item Name
1 Venturi o-ring
2 Spring
3 Check ball moved OFF valve seat
4 Chemical injection fitting
5 Chemical injection venturi
6 Discharge port
7 Chemical solution reservoir
8 Siphon tube strainer
9 Chemical siphon tube
Figure 2.6 — Low Pressure Suctionof Chemical Injection
System

10
When the pump is in the high pressure mode, the chemical
injector ball is forced against its seat, cutting off the siphon
effect and preventing water from back-flowing into the
chemical reservoir. Figure 2.7 depicts this high pressure
condition.
The chemical injector must be carefully sized for the system.
Too small of a venturi orifice will result in too low a
pressure and too much chemical will flow into the stream.
Too large an orifice will cause too much pressure at the
venturi throat and the injector will not work.
Easy Start Valve
Certain larger Generac Portable Products®
pressure washers may be equipped with an easy start valve.
This patented device relieves pump outlet pressure during
engine cranking so that it is easier for an individual to pull
the recoil starter rope.
Figure 2.8 depicts a Generac Portable
Products® medium frame pump in its starting condition.
Inlet water is connected to the pump’s garden hose
connector. Air has been purged from the pump’s water
passages. The check ball is attached to its restraint magnet
(magnet not shown).
In this condition, the pump’s internal water pressure is at
garden hose pressure. Water is free to circulate throughout
the pump without restriction, thus permitting an easier pull
on the starter rope.
As soon as the engine starts, water flow forces the check
ball against its seat, closing the garden hose pressure water
passage. Pressure within the system becomes regulated by
the unloader valve setting and the nozzle restriction.
Section 2 • Pressure Washer Components
Portable Pressure Washer Familiarization and Troubleshooting Guide
Item Name
1 Ball shown seated, cutting off chemical
flow
2 Chemical injection fitting
3 Siphon tube
4 Check ball seat
5 Venturi throat
Figure 2.8 — Starting Condition
Item Name
1 Location of restraint magnet (not shown)
2 Check ball shown attached to magnet
3 Inlet water channel
Figure 2.7 — High Pressure Cut-off of Chemical Injection
System

11
Bypass refers to the direction of fluid flow as the water
recirculates through the pump. Bypass occurs when the
normal flow of water through a nozzle is shut off.
Figure 2.9 depicts the pump in the bypass condition with the
engine running and the spray gun trigger released.
Figure 2.10 depicts the pump in a normal operating
condition with the engine running and the spray gun trigger
depressed.
High Pressure Hose
Generac Portable Products® uses excellent
quality high pressure hoses appropriate for each pressure
washer model. Hose length, hose internal diameter, and
hose pressure rating are all factored into the overall design
of the pressure washer system.
Hose specification factors include: gallons per minute rating
of the pump, pressure rating of the pump, and pressure
drop over the length of the hose between the pump and the
spray gun. Additional factors may also be used.
Accessory hoses are available to lengthen the hose from its
stock length. Generac Portable Products® does
not recommend exceeding a total length of 100 feet
between pump and nozzle because excessive length may
adversely affect chemical injection and adequate high
pressure operation.
Spray Guns
Generac Portable Products® uses several types
of spray guns for different model pressure washers. A
diagram of a typical spray gun with the trigger closed is seen
in Figure 2.11.
Section 2 • Pressure Washer Components
Portable Pressure Washer Familiarization and Troubleshooting Guide
Figure 2.11 — Typical Spray Gun Mechanism
Item Name
1 High pressure inlet connector
2 Spray gun body
3 Valve body
4 Valve return spring
5 Check ball
6 Check ball valve seat
7 Wand body
8 Trigger
9 Safety latch in lock position
Figure 2.10 — Normal Operating Condition
Item Name
1 Outlet pressure water stream
2 Trapped line pressure piston shown in open
condition
3 Easy start check ball against its seat
4 Unloader spindle assembly
5 Inlet water channel
Figure 2.9 — Bypass Condition
Item Name
1 Outlet pressure water stream
2 Trapped line pressure piston shown in closed
condition
3 Easy start check ball OFF its seat
4 Unloader piston assembly
5 Inlet water channel

12
Pulling back on the trigger moves the spray gun check ball
off of its seat, as shown in Figure 2.12. The water then flows
through the open valve and out of the wand to the nozzle.
When the trigger is released, the valve shuts against its seat
and the water flow is stopped. This condition causes the
pump to enter the bypass mode.
CAUTION: Spray guns and wands are rated for
maximum pressure and flow rate. Use of an
incorrect spray gun and wand can be dangerous and
will adversely affect pump performance. If
replacement becomes necessary, you must replace
the gun as an assembly. Use only the spray gun and
wand listed in the “Repair Parts” section of the
owner’s manual for the specific pressure washer
model being serviced.
Spray Wands and Nozzles
The spray nozzle is critical to proper operation of a
pressure washer. The nozzle restricts the liquid flow and
allows the required pressure to develop. The smaller the
nozzle orifice, the higher the system pressure. Use of a
nozzle having too large an orifice will result in a reduced
system pressure.
In addition to establishing system pressure, the nozzle
breaks the liquid into droplets, forms the spray pattern, and
propels the liquid in the proper direction.
Several different types of spray nozzles may be used. The
most popular type provides adjustable pressure and spray
patterns. For Generac Portable Products®
nozzles, slide the nozzle backward for High Pressure spray;
push the nozzle forward for Low Pressure spray; twist the
nozzle clockwise for a Fan Spray Pattern; and twist the
nozzle counterclockwise for a Narrow Stream.
In addition, Generac Portable Products® offers
several accessory nozzles, such as a rotating brush, utility
brush, and turbo nozzle.
DANGER: Do not attempt to adjust pressure or
spray pattern while spraying. Never place your hand
in front of the spray nozzle to adjust pressure or
spray pattern.
Refer to the Owner’s Manual for the specific pressure
washer model for correct operating instructions.
Section 2 • Pressure Washer Components
Portable Pressure Washer Familiarization and Troubleshooting Guide
Figure 2.12 — Spray Gun - Trigger Open

13
Section 3 • General Information
Portable Pressure Washer Familiarization and Troubleshooting Guide
Part 1 - General Maintenance
This section describes the general maintenance procedures
recommended for pressure washer components that are
common across product lines.
Chemical Injection System
Before each use, inspect the chemical injection suction hose
strainer. Clean as necessary, or replace if damaged, torn or
perforated.
Examine the chemical suction hose and replace if damaged.
Rinse the chemical injection system thoroughly after each
use by siphoning several pints of clean water through the
system.
Inlet Water Supply Connector
The pressure washer may be equipped with a “Quick
Disconnect” type connector for convenient attachment of
the inlet water supply. This type of connector, depicted in
Figure 3.1, operates easily if the o-ring is periodically
lubricated with a petroleum jelly.
The water supply quick-disconnect must be correctly
installed on the supply hose and the pressure washer or its
inlet supply filter will not be effective.
Inlet Supply Filter/Strainer
Remove the quick disconnect from the hose and inspect the
inlet water strainer. It should be oriented so that the
pointed part (the screen) points away from the pump
(towards the garden hose).
A typical inlet supply connection is seen in Figure 3.2. Clean
the strainer or replace it if it is damaged, torn, or
perforated. Reassemble the connectors, using petroleum
jelly as necessary to ease the connections.
Hose, Spray Gun and Wand Systems
With the pressure washer OFF, inspect the hose connection
to the spray gun. Make sure it is tight. Test the trigger by
squeezing it and making sure it springs back to the OFF
position when released. Set the safety latch to ON and and
test the trigger, making sure the trigger cannot be squeezed.
With the pressure washer ON and the trigger latched OFF,
verify the absence of leaks from the spray gun.
With the pressure washer OFF, inspect the high pressure
hose for cuts, leaks, abrasions, bulging, kinking, or abuse.
With the pressure washer ON and the trigger latched OFF,
verify the absence of leaks from the hose.
DANGER: Water spraying from a leaking hose can
inject material into the skin or cause serious injury.
Never attempt to repair high pressure hoses. Replace
the hose with a high quality hose that meets the
minimum pressure rating recommended by the
manufacturer.
An o-ring maintenance kit for each model is available to
refurbish all connection seals.
GENERAL INFORMATION
Figure 3.1 — Quick-Disconnect Hardware
Figure 3.2 — Inlet Supply Strainer

14
Spray Nozzle Servicing
If the spray nozzle becomes clogged with dirt, excessive
pump pressures may develop. A nozzle that has become
partly clogged will demonstrate a ‘pulsing’ sensation during
use. If the nozzle becomes clogged or partially restricted, it
can be cleaned as follows:
1. Shut down the engine and turn off the water supply to
the pump.
2. Put on your safety glasses, as there could be trapped
pressure behind a totally-clogged nozzle.
3. Disconnect the wand from the spray gun.
4. As seen in Figure 3.3, use a 5/64 inch (2mm) Allen wrench
to remove the nozzle from the end of the wand.
5. Use a length of wire similar to that seen in Figure 3.3 to
free any dirt from the nozzle.
NOTE: If desired, a 5/64 inch (2mm) wrench can be
ordered by specifying Generac® nozzle kit part
number 96961. A length of 17 gauge (0.039 inch)
wire may be used to clean the nozzle. If desired, a
nozzle cleaning rod may be ordered by specifying
Generac® nozzle kit part number 96869.
6. Remove any additional dirt from the wand by back-
flushing with water, as described below and shown in
Figure 3.4.
a. Hold the water supply against the wand and back-flush
for about 30 seconds to 1 minute.
b. While flushing, move the nozzle collar between stream
and spray positions and between the low and high
pressure positions.
7. Use the 5/64 inch (2mm) Allen wrench to reinstall the
nozzle into the wand. DO NOT OVERTIGHTEN.
8. Reattach the wand to the spray gun.
9. Reconnect the inlet water supply to the pump and turn
on the water.
10. Start the engine and test operation.
Section 3 • General Information
Portable Pressure Washer Familiarization and Troubleshooting Guide
Figure 3.3 — Nozzle Removal and Cleaning
Figure 3.4 — Back-flushing the Wand

15
Part 2 - Lubrication
All pressure washers require oil lubrication of the piston
mechanism in order to maintain long-term reliability and
service. Certain early model Generac Portable
Products® pressure washers incorporate sight glasses
or dipsticks to be used to monitor pump oil levels. Later
Generac Portable Products® models have
improved designs that eliminate the need to routinely
monitor oil levels or to change lubricating oil.
This section describes how to check and change pump oil on
early Generac Portable Products® pressure
washer systems. If servicing a non-Generac Portable
Products®-manufactured pump, please refer to the
maintenance instructions provided with that specific system.
Check Pump Oil Level
Certain pressure washers may be equipped with a glass sight
gauge, as depicted in Figure 3.5.
Always check pump oil level with the unit resting on a level
surface. Oil should be at the full mark on the sight gauge
(near the center). On units equipped with an oil dipstick, oil
level should be near the full mark. Add recommended pump
oil as required, to the full mark only.
Change Pump Oil
WARNING: DO NOT change pump oil unless the
pressure washer Owner’s Manual requires this AND
your pump is equipped with a pump drain plug.
Please refer to the maintenance instructions that were
shipped with your non-Generac Portable
Products®-manufactured pump if it is necessary to
change pump oil. Pay particular attention to the
manufacturer’s recommended torque values when tightening
drain plugs and breather/dipstick caps.
To change oil in Generac Portable Products®-
manufactured pumps, refer to Figure 3.5 and proceed as
follows:
1. Place a suitable container under the pump drain plug.
2. Remove the oil fill cap (breather cap) from the top of the
pump.
3. Remove the pump drain plug from the bottom of the
pump. Drain oil completely into the container.
4. When all oil has drained, reinstall the pump drain plug and
tighten to the torque value specified in the Torque Chart,
found on the exploded view in the chapter for your
pump.
5. Insert a funnel into the oil fill cap opening and add the
recommended oil until the oil level reaches the full mark.
Oil capacity and type is listed in Part 1, earlier in Section
3.
6. When oil is at the proper level, install and tighten the oil
fill cap to the torque value specified in the Torque Chart,
found on the exploded view in the chapter for your
pump.
Section 3 • General Information
Portable Pressure Washer Familiarization and Troubleshooting Guide
Figure 3.5 — Sight Gauge on Side of Pump
Item Name
1 Breather cap/oil fill location
2 Drain plug
3 Sight gauge location

16
Part 3 - Storage
Pump Storage
Water should not be allowed to remain in the pump for
long periods of time. Sediment can become deposited on
pump parts, resulting in pump ‘freeze-up’.
To protect the pump against water sediment buildup,
proceed as follows after each use:
1. If the chemical injection siphon was used, flush the system
as follows:
a. While running the pressure washer with the nozzle set
to low pressure mode, place the chemical siphon tube
and its strainer into a pail of clear water.
b. Permit siphon action to continue for two or three
minutes to flush the system.
c. Shut off the engine and let it cool. Squeeze the spray
gun trigger to relieve trapped line pressure. Then
remove all hoses.
WARNING: Never start the engine or operate
the pump unless the proper water supply is
connected. Any attempt to run the pump without the
correct water supply will result in damage to the
pump.
2. With the engine RUN/STOP switch in the STOP position,
pull the engine’s recoil starter about six (6) times. This
should remove most of the liquid from the pump.
3. Drain water from the high pressure hose, then coil the
hose and stow it properly.
4. Store the unit in a clean, dry area.
Protection Against Freezing
To protect the pump against freezing, proceed as follows:
1. Draw automotive windshield washer fluid into the pump:
a. Connect a three (3) foot length of garden hose to the
pump inlet.
b. While holding the open hose end higher than the
pump, pour the washer fluid into the length of hose.
c. With the engine RUN/STOP switch in the STOP
position, pull the engine’s recoil starter handle two or
three times. This should replace most of the water in
the pump with anti-freeze solution.
Purging Air From the System
Prior to use, the pressure washer pump, hose, and spray gun
should be purged of air. To do this, proceed as follows:
1. Prepare the pressure washer for use as outlined in the
Owner’s Manual. Make sure a proper water supply is
connected and turned ON.
2. Put on your safety goggles and remove the wand from the
spray gun.
3. Pull the trigger on the gun and hold open.
4. When the water flow is steady and constant, release the
trigger to turn off the flow.
5. Reattach the wand to the gun.
The system is now ready for use.
Section 3 • General Information
Portable Pressure Washer Familiarization and Troubleshooting Guide

17
This section describes the small frame pump assemblies powered by electric motors. This small frame electric pump may
also be referred to as ‘EE’ or ‘GPW-EE’ or ‘Economy Electric’ pumps.
The small frame electric pump has the following features:
• 1100 to 1300 PSI water pressure
• 1.5 to 1.8 Gallons per minute flow
• Axial Cam Design
• Stainless Steel Pistons
• Fixed Pressure Unloader
• Chemical Injection System or Foamer Bottle available
• Grip-Start™ - Automatically turns on the pump when spray trigger is pressed
• Safety Flow™ switch - Pump will not operate unless water supply is turned on.
• Oil bath, helical gear drive system
• 14 Amp Universal motor
• Designed to UL 1097 Double Insulation standards
Part 1 - Specifications and Views
Performance specifications for Generac Portable Products® small frame electric pumps, sectional and exploded
views, and a table showing recommended torque values are provided below.
Performance Specifications
+ Pressure (in pounds per square inch) is adjustable up to the unit's rated pressure.
* Flow rate is given in gallons per minute.
Pump assemblies are listed by part number and were current at time of publication. Other pump assemblies will become
available as our products evolve.
SMALL FRAME ELECTRIC PUMP
Section 4 • Small Frame Electric Pump
Portable Pressure Washer Familiarization and Troubleshooting Guide
Model Rated Pump Head Flow Rate* Piston Oil Type/
Part No. Pressure+ Material Capacity
0762-0 1250 Aluminum 1.5 Stainless Steel 80W90/60ml
0776-0 1300 Aluminum 1.5 Stainless Steel 80W90/60ml
0766-1 1250 Aluminum 1.5 Stainless Steel 80W90/60ml
0793-0 1250 Aluminum 1.5 Stainless Steel 80W90/60ml
1007-0 1250 Aluminum 1.5 Stainless Steel 80W90/60ml
9606-0 1100 Aluminum 1.8 Stainless Steel 15W40/150ml
9737-0 1150 Aluminum 1.8 Stainless Steel 15W40/150ml