Zenith NA428 User manual

202890 Rev-5 Dec 2, 2019
NA428-
NA857
Stationary Emergency
Industrial engines
Operator Manual
and Maintenance Log

202890 Rev-5 Dec 2, 2019

Rev-5 Dec 2, 2019
Service Parts
To ensure that your engine continues to run reliably and
efficiently for as long as possible, use only genuine Zenith
Power Products (ZPP) parts.
For genuine ZPP service parts for your engine, or for technical
assistance in servicing your engine, call:
1-276-525-4760
Hours:
Monday-Thursday: 8:00 – 5:00 Eastern Time
Friday: 8:00 – 12:00 Eastern Time
Maintenance Providers
Maintenance and repair services may be performed by you or
any qualified engine service provider that you choose.
However, your engine warranty does not cover damage or
failure caused by improper maintenance or repairs.
Operators Manual & Maintenance Log Storage & Use
Store this Operators Manual and Maintenance Log in a safe,
visible place by your engine. The maintenance log must be
updated whenever your engine is serviced.
Disclaimer
All information and specifications in this manual are based on
the latest data available at the time of the publication. Zenith
Power Products reserves the right to make changes or
improvements at any time without notice.
For additional information, see:
www.ZenithPowerProducts.com

1 Rev-5 Dec 2, 2019
TABLE OF CONTENTS Pa
g
e
U.S. EPA Le
g
al Requirements 2
Safet
y
S
y
mbols & Precautions 3
Fuels 6
Startin
g
, runnin
g
, and stoppin
g
the en
g
ine 7
Engine maintenance
xSchedule
xAir filter
xBattery
xPCV system
xEngine coolant, radiator, and cooling system
xDrive Belt
xEngine oil & filter
xChecking for gas leaks
xNatural Gas & LPG fuel lock-off valves
xOxygen sensor
xSpark plugs, wires, Distributor cap and rotor
8
Diagnostics
xHow to retrieve fault codes
xDiagnostic Trouble Code (DTC) List
23
Specifications 31
En
g
ine Identification 32
Engine Warranty
xWarranty provisions
xBase warranty period
xEmissions-related warranty period
xOwner's obligations
xComponent lists
33
Maintenance Lo
g
35

2 Rev-5 Dec 2, 2019
U.S. EPA Legal Requirements
The ZPP NA428 & NA857 Natural Gas and LPG Vapor engines have
been certified by the U.S. Environmental Protection Agency (EPA) as
Stationary Emergency Engines. It is illegal to operate these engines in
a prime or emergency mobile application or a prime stationary
application.
Per 40 CFR 60.4243(d), you may operate your Stationary Emergency
Engine for an unlimited number of hours in emergency situations. You
may also operate your engine for up to 50 hours per year in non-
emergency situations for maintenance purposes.
To ensure emissions compliance, the U.S. EPA requires you to do one of
the following two options:
1. Operate and maintain your engine as specified in this Operators
Manual. In addition, you are required by law to keep detailed
maintenance records.
2. If you operate your engine as a Stationary Emergency Engine
but do not operate and maintain your engine as specified in this
Operators Manual, your engine will be considered a non-certified
engine.
In this case, you must:
xKeep a maintenance plan and records of conducted
maintenance.
xTo the extent practicable, maintain and operate the engine in
a manner consistent with good air pollution control practice
for minimizing emissions.
xConduct an initial performance test within 1 year of engine
startup to demonstrate compliance (NA857 only). Contact
your regional EPA office for instructions on how to conduct
an initial performance test.
Per section 113 of the U.S. Clean Air Act, failure to abide by these legal
requirements can result in fines up to $29,750 per day.
A maintenance plan and log are provided at the back of this manual for
you to record your engine maintenance. Update the log each time you
service your engine.

3 Rev-5 Dec 2, 2019
Spare Page

4 Rev-5 Dec 2, 2019
SAFETY SYMBOLS
This section identifies the ISO 8999 symbols that may be used in this
manual.
Battery
Electrical
hazards
Engine coolant
fill level
Engine
coolant
temperature
Engine oil fill
level
Engine oil
pressure
Hot surface
warning
Warning
Read the
handbook
No Smoking or
Flame

5 Rev-5 Dec 2, 2019
SAFETY PRECAUTIONS – STARTING
WARNING
Starting an engine incorrectly may cause injury to the operator
and/or cause damage to the engine. Engine operators must be
instructed in the correct procedures before attempting to start
an
y
en
g
ine.
Before Starting
.
xInspect the engine, intake, exhaust, cooling system, and drivetrain to
verify that the engine is fully assembled and not in the process of
being serviced.
xEnsure the engine is free to turn without obstruction.
xCheck that all safety guards are in their correct position and secure.
xCheck that the coolant level in the radiator overflow bottle is between
"Add" and "Full".
xCheck that the oil level on the dipstick is between "Add" and "Full".
xCheck that the fuel supply is connected, shut-off valves are open,
and there are no leaks.
xIf a LPG fuel system is being used, verify that there is fuel in the
cylinder/tank.
xIf a natural gas fuel system is being used, verify that the correct fuel
supply pressure is being supplied to the engine.
xCheck that the battery is connected and charged.
xWhen possible, disengage any driven equipment while starting.

6 Rev-5 Dec 2, 2019
SAFETY PRECAUTIONS – ELECTRICAL
The battery produces flammable and explosive hydrogen gas.
The battery electrolyte contains poisonous and corrosive
sulfuric acid. The precautions listed below must be followed to
ensure operator safet
y
.
xDo not smoke or allow any flame near the battery.
xWith the engine stopped and the ignition switch in the OFF
position, disconnect the negative battery cable from the battery
before working on the engine.
xBe careful not to short circuit battery positive to ground with tools
when working on the engine.
xAvoid getting battery electrolyte in your eyes or on your skin or
clothes. If electrolyte gets in your eyes, flush with clean water
immediately and get medical help. If electrolyte gets on your skin,
wash immediately with soap and water and get medical help if you
feel pain or burning. Remove and wash any clothing that is
exposed to electrolyte.
xNever remove any electrical cables while the battery is
connected in the circuit.
xBe careful to not short-circuit or cross battery positive and
negative.
xNever ‘flash’ any connection to check the current flow.
xThe battery and alternator must be disconnected before
commencing any electric welding when a pole strap is directly or
indirectly connected to the engine.
xWhen charging the battery, only do a slow charge (5 A or less),
and ensure there is good ventilation.

7 Rev-5 Dec 2, 2019
FUELS
Natural gas and LPG are combustible gases, and can be explosive if
leaked and contained in a confined area. Keep cigarettes and all other
flame sources away from these areas.
If you can hear a fuel leak, shut off the fuel supply at the source
immediately and fix the leak or have it serviced. Check the entire fuel
supply line from the cylinder/tank to the engine for leaks with a soapy
water bubble mixture anytime a cylinder/tank is changed or the fuel
supply line is worked on. Fuel leaks should also be checked as part of
the regular engine maintenance.
Depending on your engine and fuel system configuration, your engine is
designed to run on natural gas and/or vapor LPG. The fuel requirements for
each are discussed below. See the "SPECIFICATIONS" section for the required
fuel supply pressures for each fuel.
Natural Gas
Your engine is certified to run on "pipeline-quality natural gas". EPA defines
pipeline-quality natural gas as being composed of at least 70% methane by
volume or having a heating value of 950-1100 BTUs per cubic foot. In addition,
pipeline-quality natural gas must be provided by a supplier through a pipeline. If
your natural gas supply does not meet these specifications, your engine is
considered to be being operated as a non-certified engine. See "U.S. EPA Legal
Requirements" at the front of this manual.
LPG
In order to maintain emissions compliance and the engine warranty, use
commercial-grade HD-10 or better LPG.
Liquid LPG is drawn off of the bottom side of a LPG tank or cylinder and is a
liquid until it has passed through the regulator/vaporizer, at which point it is
vaporized to a gas. If you connect vapor LPG to a liquid LPG fuel system, you
may starve the engine for fuel, causing it to produce low power and excessive
emissions.
Vapor LPG is drawn off of the top side of a LPG tank or cylinder and is a gas
from the tank/cylinder through to the engine intake. If you connect liquid LPG to
a vapor LPG fuel system the fuel will not vaporize properly, causing the engine to
run rich, produce low power and excessive emissions.

8 Rev-5 Dec 2, 2019
STARTING, RUNNING, & STOPPING THE ENGINE
Observe the safety precautions listed in "SAFETY PRECAUTIONS -
STARTING" before starting the engine.
Starting the engine
xTurn the key switch to the ON position and verify that the MIL is
illuminated. If not determine why the lamp is not working.
xTurn the key switch to the START position and hold until the
engine has started.
xRelease the key promptly after the engine starts to avoid
grinding the starter.
xDo not crank the engine for more than 15 seconds at a time.
xAllow at least 30 seconds between cranking attempts.
xIf the engine does not start after 3 starting attempts, review the
"Before Starting" checklist.
Running the engine
xDo not race or fully load the engine during the first 3 minutes of
operation.
xVerify that the "CHECK ENGINE" light is off while the engine is
running. If it is on, refer to the DIAGNOSTICS section.
xVerify that there are no fuel, coolant, or oil leaks while the engine
is running. If there are leaks, stop the engine and fix them or
have the engine serviced.
xListen to the engine. If you hear an abnormal noise while the
engine is running, turn it off and correct the problem or have the
engine serviced.
xNo adjustments are necessary to the fuel or ignition systems.
Stopping the engine
xIf the engine has been running under load and is hot, run the
engine at no load for 3 minutes to allow the engine to cool before
stopping the engine.
xStop the engine by turning the key switch to the OFF position.
The engine may run-on for 1-5 seconds while the fuel is depleted
from the carburetor and the air/fuel mixture is depleted from the
intake manifold.

9 Rev-5 Dec 2, 2019
ENGINE MAINTENANCE
You should properly maintain your engine for the following reasons.
xYou are legally required to maintain your engine and keep
maintenance records to ensure emissions compliance. See
"U.S. EPA Legal Requirements" at the front of this manual.
xYour engine warranty will be void if the engine is not properly
maintained.
xKeeping your engine properly maintained will ensure the best
engine life, power, and fuel economy.
Scheduled Maintenance
A schedule of the required engine maintenance tasks is listed on the
following page. The scheduled maintenance should be performed when
the engine reaches the specified operating hours or the specified months
have elapsed, whichever comes first.
Daily Maintenance
In addition to the scheduled maintenance, daily checks are required to
keep your engine running properly. These checks are listed in the
"SAFETY PRECAUTIONS - STARTING" and "STARTING, RUNNING, &
STOPPING THE ENGINE" sections.
Maintenance Log
Keep a record of your engine's scheduled maintenance in the
Maintenance Log at the back of this manual.

10 Rev-5 Dec 2, 2019
MAINTENANCE
Periodic maintenance should be performed after specified Years 1 2
intervals have elapsed in years or hours, whichever comes first Hours 250 500
(A) I
II
II
II
(A) C C
(A) R R
(A) R R
Distributor Cap & Rotor
(A)
Check fuel hoses and fittings for gas leakage (B) I I
Fuel lock-off valves
Notes: A) Under heavy duty operating condition, more frequent maintenance may be necessary
B) At time of LPG cylinder replacement, inspect tank connections for leakage with soapy water.
Abbreviations: I = Inspection
R= Replace
A= Adjust
C= Clean
PCV system
Spark Plug Wires
Oxygen sensor
Drive Belt
Radiator outside
Engine oil
Oil Filter
Engine coolant (L.L.C.)
ADDITIONAL MAINTENANCE REQUIREMENTS
Spark Plugs
Air filter
Battery
ZPP NA428 & NA857 STATIONARY EMERGENCY ENGINE AND
This table lists the periodic maintenance required to ensure quality performance

11 Rev-5 Dec 2, 2019
EMISSIONS CONTROL SYSTEM MAINTENANCE SCHEDULE
and good reliability of the engine and emission control system in your application.
INTERVAL
34567
750 1000 1250 1500 1750
RI
IIIII
IIIII
IIIII
CCCCC
RRRRR
RRRRR
I
I
I
I
I
FOR LPG FUEL SYSTEM
IIIII
I

12 Rev-5 Dec 2, 2019
STORAGE
If the Stationary Emergency engine will not be placed in service
right away, or if the unit is removed from service and will be stored
for an unanticipated length of time, please follow the steps below
to avoid damage to your engine.
1. Clean the air cleaner evacuator valve and body.
2. Replace air filter.
3. Drain, flush and fill the cooling system with the correct
antifreeze engine coolant mixture to protect the engine to
the lowest anticipated temperature.
4. The battery does not need to be removed, unless
extended storage will be more than 30 days, or if
temperatures will fall below freezing. The battery MUST be
fully charged to prevent freezing. Disconnect negative and
positive battery cables to prevent discharge and damage
to controls and other connected components. Check
battery charge every 90 days.
5. Remove all drive belts.
6. Cover the exhaust stack with a can or other appropriate
cover to prevent the entry of rainwater, debris, or animals.
DO NOT seal up tight as this may cause condensation to
collect inside the exhaust system.
Do not prepare engine for storage if it is in-
use for Emergency Standby purposes.
Only prepare if unit is Not in Use.

13 Rev-5 Dec 2, 2019
AIR FILTER
NA428 Air Filter: 200476
NA857 Air Filter: 200469 Primary
200289 Secondary (If Equipped)
Inspection
1. Remove air filter element from enclosure.
2. Tap filter to knock off loose dirt.
3. Visually check filter.
4. If filter is clean, reinstall old filter.
If filter is dirty, replace with a new filter.

14 Rev-5 Dec 2, 2019
BATTERY
The battery produces flammable and explosive hydrogen gas.
The battery electrolyte contains poisonous and corrosive
sulfuric acid. Review the safety precautions in "SAFETY
PRECAUTIONS - ELECTRICAL" before workin
g
on the batter
y
.
Battery Specifications
Nominal Voltage: 12 V
Cranking Amps: 750
Cold Cranking Amps: 600
Ampere Hours 56
Battery voltage during alternator charging: 14.0 -15.0 V
Fully charged battery with key off @ 20 C (68 F): 12.5 -13.0 V
Half charged battery with key off @ 20 C (68 F): 12.0 - 12.5 V
Discharged battery with key off @ 20 C (68 F): less than 12.0 V
Battery electrolyte inspection
1. Check electrolyte level.
2. If low, top off with distilled water. Do not overfill.
Battery corrosion inspection
1. Check battery posts and clamps for corrosion.
2. If corroded, remove negative cable first, then positive.
3. Clean both posts and both clamps with a small wire brush.
4. Reconnect cables, positive cable first.
If the engine is cranking slowly or not at all:
1. Remove the battery negative lead from the battery.
2. Remove the positive lead from the battery.
3. Clean the battery posts and cables with a small wire brush.
4. Replace leads, positive lead first.
If the engine is still cranking slowly or not at all:
1. Remove the battery negative leads.
2. Recharge the battery in a well-ventilated area.
3. Reinstall the battery.
If the engine is still cranking slowly or not at all:
Replace the battery.

15 Rev-5 Dec 2, 2019
PCV SYSTEM
The Positive Crankcase Ventilation (PCV) system recirculates the
crankcase blow-by gases into the intake manifold to be combusted in the
engine. When the blow-by vapor pressure is high enough to overcome
the spring pressure in the PCV valve, the valve opens to allow blow-by
vapor into the intake manifold for combustion along with the fuel/air
mixture.
Inspection & Cleaning:
1. Remove and inspect the breather hose and fitting.
Clean or replace if needed.
2. Remove and inspect the PCV hose.
Clean or replace if needed.
3. Remove and inspect the PCV valve.
Clean the PCV valve if needed.

16 Rev-5 Dec 2, 2019
ENGINE COOLANT, RADIATOR, AND COOLING
SYSTEM
To avoid being scalded or burned, never remove the radiator cap
unless the engine is off and coolant has fully cooled. The
coolant in the radiator is pressurized when hot and may boil over
when the radiator cap is loosened.
When using antifreeze coolant, mix the antifreeze coolant with water,
observing instructions attached to antifreeze container. Use only
antifreeze approved for aluminum components in a 50/50 mixture ratio.
Clean radiator outside
Clean outside of radiator with dry compressed air.
Inspect cooling system, hoses and connections
Check hoses and fittings for loose connections or for any sign of oil
deterioration or soft spots in the hoses. Retighten connections or replace
hoses if needed.
Check coolant level. If low, top off coolant with a premixed 50/50 mixture
of antifreeze and water.
Engine Coolant Replacement
1. Open overflow bottle cap.
2. Drain old coolant.
3. Flush system with fresh, clean water.
4. Slowly refill system with premixed 50/50 antifreeze/water mixture.
5. Idle engine with radiator cap off to allow air to escape.
6. Top off coolant in overflow bottle if needed.
7. Stop engine.
8. Replace radiator cap and close overflow bottle cap.

17 Rev-5 Dec 2, 2019
DRIVE BELT
428 Belt P/N: 201368
857 Belt P/N: 200196
Inspection
Check the belt for visible cracks, missing chunks, and fraying. Small
cracks on the inside of the belt are OK. Replace the belt if cracks are
visible on the outside of the belt, chunks are missing from the inside of
the belt, or the belt is frayed.
Belt Tension
Measure the belt tension midway between the alternator and water pump
pulley as specified by the arrow in the left figure above. Use a tensioning
tool such as the one shown in the right figure above (OTC 6673LG or
equivalent).
Deflection:
A second method of measuring belt tension is to apply a force of 98N
(10kg, 22lb), and measure the deflection between the alternator and
water pump pulley. If the belt tension is not as specified, adjust it.
DEFLECTION
New belt 8.5 ~ 9.5mm
(
0.3346 ~ 0.3740in.
)
Used belt 9.5 ~ 11.0mm
(
0.3740 ~ 0.4331in.
)