Onan JB Series User manual

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OPERATOR'S MANUAL
:I
FOR
JB
SERIES
ELECTRIC GENERATING SETS
FORM NUMBER
967-0123
ISSUE DATE
(Spec AA)
Printed in U S. A
2-77

SAFETY PRECAUTIONS
The fol lowing symbols in th is manual Signal poten-
tially dangerous conditions to the operator or e
quip -
ment. R
ea d this manual carefully. Know when these
co
nd itions can exist. Then. take necessary steps to
protect personnel
as well as equipment.
IWARNING' Onan uses this symbol
throughout this manual to
warn
of possible serious personal injury.
Fuels. electric al eq uipment, batteries, exhaust gases
and moving parts present potentialhazards that could
result in serious. person
al Injury.Take care In f ollo w-
ing these recommended procedures.
• Use Extreme Caution Near G as oline, Gaseous
Fuel And Diesel Fuel. A
constant potential ex-
plosive or fire hazard exists.
Do not fill fuel tank near unit wi th engine running.
Do not smoke
or use open flame near the unit or
the fuel tank.
Be su
re all fuel supplies have a posItive shutoff
v al ve.
Fu el lines must be of steel piping, adequately
secu
red and free from leaks. Do no! use copper
piping on flexible lines
as copper becomes
hardened and b
ri ttle. Use black pipe on natural
gas or gaseous fuels,
not on gasoline or diesel
fuels.
Pi pi ng at the engine should be approved
fl exible line.
Have a fi
re extinguisher nearby Be sure ex-
ti nguisher is properly maintained and be famlli r
wi
th Its proper use. Extinguishers rated ABC by
the NFPA are appropriate f
or al! applications.
Consult the local fire department f
or the correct
type of extinguisher
for various applications
• Guard Against Electric Shock
Remove el ec t nc power before removing protec-
tive shields or t OUC hing electricalequipmen t. Use
rubber insulative mats placed on
dr y W OOd plat-
forms over
fl oors that are metal or concrete Wh en
around electrical equipment Do not w ea r damp
clothing (particularly wet
shOes) or allow skin
surfaces
to be damp when handling electrical
equipm
ent
Jewelry Is a good cond ucto r of elect ri city an d
should be removed when working on elect
ri cal
equipmen
t.
Always use an appro pr iately si zed. approved
do
uble-thr ow transfer s witch with any standby
generator set DO NOT PLUG PORTABLE
OR
STANDBY SETS DIRECTLY INTO A HOUSE
RECEPTACLE TO PROVIDE EMERGENCY
POW
ER. It is possible for current to flow from
generator Into the uti
lity line. This creates ex-
treme hazards to anyone working on lines to
restore pow
er .
U
se extreme caution when working on electrical
components. High voltages
ca u se In jury or death.
F
ollow all state and local electricalcodes. Havea ll
electrical Installations perfo rm ed by a qualified
licensed electrician.
•
Do Not Smoke While Servicing Batteries
L ead acid batteries emit a hig hly explosive
hydrogen g
as that can be ignited by electrical
arcing
or by smoking.
• Ex haust Gases Are Toxic
Provide an adequate exhaust system to properly
expel discharged gases. Check exhaust system
regula
rl y f or leaks.Ensure that exhaust manifolds
are secure and
not warped.
Be sure the unit ISwell ventilate
d.
• Keep The Unit
And Surrounding Area Clean.
Remove all or! depOSits. Remove all unnecessary
gr ease and 011 from the uni t. Accumulat ed gr ea se
an d oil can cause overh ea ting and subsequent
engine damage and may
pr es ent a potential fire
hazard.
..
Disposeo foily rags. Keep the floor c le an and dry .
•
Protect Against Moving Parts.
AVOid moving paris of the unit. Loo se jackets.
shir
ts or sleeves shOUld not be permitt ed because
of the danger
of becoming caught In moving
parts.
Make
su re al ! nuts and bolts a re secu re . Keep
power shields and guards
In position
If adjustments must be made while the unit is
running, use extreme caution around hot
manifol ds . moving parts. etc.
Do not work on t
hiS equipment when mentally or
physically fatigued

GENERAL INFORMATION
~,
. MODEL IDENTIFICATION TABLE OF CONTENTS
When the instructions in this manual refer to a TITLE PAGE
specific model
of generating set, identify the model' General Information
.......................... 1
by referring tothe MODEL and SPECIFICATION NO. Specifications . .. . . . . . .. .. .. .. .. . . .. .. . . . .. .. . 2
as shown on the Onan nameplate. Electrical Descrip.tion. . .. . . .. . . . . . . . .. . .. . . .. . .. . . .. . . .. 4
characteristics are shown on the lowerportion
of the Installation .. .. .... ..
.. . . .. . . .. . .. . . .. . . . . . .. . 7
set nameplate.
Operation. . . .. . . .. . . .. . . . .. . . .. . . . . . .. . .. . . .. 14
Adjustments. . . .
.. . .. . . . . .. . . .. . . . .. . .. . .. . . .. 17
. I General Maintenance . .. . . .. .. . . . .. . .. . . .. . .
.. 20
How to interpret MODEL and SP~C NO. Maintenance Schedule. . . . .. . . . . .. . . .. . . .. . .
.. 20'
\ Troubleshooting Guide
................... .. .. 23
Parts Information
............................ 24
7.SJ8 -3CR / 96 AA \
TT TT \
1 2 3 4
r) 1. Factory code for general identification.
2. SpecificType:
C - Indicates re.connectible.
R
'- REMOTE. Electric·starting. For permanent
installation,"can be connected to optional
accessory .equipment
for remote or. automatic
control
of starting and stopping. .
3. Factory code for optional equipment.
4. Specification (Spec) letter (advances when fac-
tory makes production modifications).
WARNING I
TO AVOID POSSIBLE PERSONAL INJURY OR
.EQUIPMENTDAMAGE, A QUALIFIEDELECTRI-
CIAN OR AN AUTHORIZED SERVICE
REPRESENTATlVE MUST PERFORM IN-
STALLATION AND ALL SERVICE.

• • • • • • • • ••
SPECIFICATIONS
For any abnormalities in operation, unusual noises from engine or
generator, loss of power, overheating, etc., contact your ONAN
dealer.
GENERAL
Nominal.dimension of set (inches)
'Height
...........•........•..... '. . . . . . . .. . . . . . .. . . . . .. . . . .. . . . . . .. . . . . .. . . . . .. 26-1/2 (673 mm)
Width
...................•......... '. ........... ..........•.. .................. . 18 (457 mm)
Length
...... ' ...............•....••........................•..•...........•..... 32-11/16 (838 mrn)
Weight (nominal)
...........•......•.... '............................................... 480 (218 kg)
ENGINE DETAILS ~
Number cylinders (vertical inline) ................................................................. 2
Displacement (cubic inch)
.................... '. .. .... ... ... . .. . .. . . .. .. . ... . .. . .. . . . . .. . . .. . . . .. 60
Cylinder bore' ............................... ' ......................................... 3..,1/4 (82.5 mm)
Piston'stroke
.. . ...... .. .•.. . .•.. . ... . ... ... . .. .. .... .. . . .. ... . ... .•... ...... . ..•... 3-5/8 (96 mm)
RPM (for 60 hertz) ................. ' ................................. :. . . . . .. . . . . .. . . .. . . . . .. .. 1800
RPM (for so hertz) ..... ' ..... , ................................................................. 1500
Compression ratio
............. ~ ............................ '. . . .. . . . . . .. . . . .. . . . . .. . . . .. . . . . .. 6.5:1
Compression ratio gas or LPG ............................. ' .............. ; ...............•.... 9.2:1
Exhaust connection (pipe tapped) .................. .............................. 1-1/4"(31.8 mm)
Governor, Internal Flyball, External Adjustment '
.. , ............................................... Yes
Centrifugal start-disconnect
switch. . . . . .. . .. . . .. . .. . . . . .. . . . .... . . . .. .. .. . . ... . .. . . . .. . . . .. . . .. Yes
CAPACITIES AND REQUIREMENTS
Battery. voltage (AC set). . . . . .. . . . . .. . .. . .. . . . . .. . . .. . . . . .. . . .. . . .. . . . . .. . . . .. . . . . .. .. . . . . .. 12 volt
Battery size", ,
'
.. SAE.group tH .." ..... ; ................................................ '. i Two in Series
Amplhr;SAE:rating -20 hr. (nominal) ........................................................ *74
,
.,Startingbystarting motor with solenoid shi.ft andover-:-run clutch ..•............•.. : ........•... ; Yes'
Battery charge',rate amperes
................. ; .................•................................ 2-5
Charge ammeter scale
....... ' ....................•.... ' .......... ' ...... : .............. ~ . .. .. .. 5-0-5
*Oil Capacity in U.S. quarts -Refill. .............. ;. . .. . . . . .. .. . .. .. .. . . .... . .. .... .. .. .3 (2.84 litre)
Ventilation Required (cfm 1800 rpm)
Engine (Pressure Cooling)
................................................. : .... 520(14.7 m3/min)
Engine (Vacu-Flo Cooling)
..................................................... :., 610 (17.3 rna/min),
Generator
.................... '. . . . . . .•. . .. . . . . . . .. . . . . .. . . .. .. . . . . . .. . . . .. . . . .. . 126,(3.6 m3 /min) .
Combustion
..................... '............................................... ,32 (0.9 m3 /min)'
GENERATOR
Output rated at unity power factor load .............................................. ~ . ; . . .. 1 phase,
Output rated at 0.8 power factor load. . .•.. .. . .... .. . .. . . . . .. . . . . .. . . .. . .. . . .. . .• . .. . .. . .. .. 3 phase
Rating (output in watts)
50 hertz AC -General Utility
.............................. '.' .........•........... : ...•. ,. .. 6000
60' hertz AC -General Utility ........ ' .............. .' ... ' ................................ ' ..... 7500.
Revolving field type generator
.........•... , ................................................... ' ... Yes,
120/240
voJt Single phase model reconnectible .........•........................................ Yes
Br~ad range 3-phase, 12 lead reconnectible ................................................... Yes
Solid state voltage regulator
•................ ' ................... ; .......................... ' ... Yes
Brushless Exciter
... , .. '. . . . . .. . . .. . . . .. . . . . .. . . . .. . . . . .. . . .. . . .. . . . . .. . . . . .•. . .. . . . . .. . .. . . .. Yes
Mobile or outdoor~operation during ambi,ent temperatures belowQoF (-17-.8°C). use 105 amp/hrrating.
* -Plus 1/2 quart (0.47 litre) for new filter.
2

TUNE-UP SPECIFICA"nONS
Cylinder head bolt torque (Ibs. ft.) .. , ....... ,""', .. ,', .. , ...... , .. , .. ,""", .... 28-30 (38-41 Nom)
Spark plug gap ..... ,:, ... ,." ... " , .. ,"" ......................... ':............ ,025(0,64 mm)
Centrifugal switch, breaker point adjustment ... ,, , ..... , ,. , .... , . , .. , ,, , •.... ,, .. , . .020 (0.51 mm)
Magneto, Pole shoe gap .. ,', ... " .. " ...... ,",.,.,"", ... , ...... , ...... , .. "... .020 (0.51 mm)
Breaker pOint setting gap ....... , . , .. , ....................... ; ........•......... ,. .020 (0.51 mm)I
Tappets*
Gasoline, Intake ....... , •. , , , , ., , ,, .. , , ,. , , , , ., . ,, , . ,', . , ,, , , , .. , .. , ..•. , ... , ... . .012 (0.30 mm)
Exhaust ,;, .............. : .................. , ........................ . .015 (0.38 mm)
Gas and Gas/Gasoline, Intake ........ ,. , .. , .... , , , ....•.......•. ; .. , .•• ,." .... ,,
.0131 (0.33 mm)
Exhaust·, •. ". ,', ... ',,',"'" " ".," " .. ,.,., .... ,' .. "','
.020 (0.51 mm)
Ignition timing sparkadvance**
(Running) Gas fuel*** ",." ... , .... " .. ,.,"""',.,""""""""',.".,"", .. ,.," 35° BrC
(Stopped) Gas fuel ",." ........... ,', .. "., .... ,"',., .. , .•...•. ,',.,',."., .. , ..... ,.". 5° BTC
(Running) Gasoline Fuel .
Flywheel magneto ... , , , ., .... , . , .... ,. , .. , .. , ... ,, .... , , ., , , ... , ,, , .. , .. . . .. . . .. . . . .. 25° BTC
Battery ......... : ...... , .... , ..... , .................... '.' ..... , ...... , ............ '. . .. 25° BTC
(Stopped) Gasoline fuel
Flywheel magneto .... " ....... , ....... ,., .... , ....... ' ............................. '..... 5° ATC
Battery ... ~ .......................................... , ..... ; .. " .. , .... ,., ... ,......... 5° ATC
, - Set valve clearance with flywheel timing mark between 10°ATC
and 45°ATC with cylinder being adjusted on power stroke,
.. -The JB series has an automatic spark advance of 30° ,
•• '- Sets with a flywheel magneto must always fire at
25° BTC, regardless of fuel.
IWARNING)
ENGINE EXHAUST GAS (CARBON MONOXIDE) IS DEADLYI
Carbon monoxide is ,an odorless, colorless gas formed by Incomplete
combustion of hydrocarbon fuels. Carbon monoxide Is a dangerous gas that
can cause unconsciousnessand Is potentiallylethal. Some of thesymptoms or
signs of carbon monoxide Inhalation are:.·
• Dizziness •
Vomiting
• Intense Headache • Muscular Twitching
• Weakness and Sleepiness • Throbbing in Temples
If you experience any of the above symptoms, get out Into fresh air
immediately.
Thebestprotection againstcarbonmonoxideinhalationisaregularinspection
of the complete exhaust system. If you notice a change In the sound or
appearance of, exhaust system, shut the unit down Immediately and have it
.inspected and repaired at once by a competent mechanic. .
If')
3

DESCRIPTION
GENERAL
An Onan ~IB Series electric generating set consists.of
a two-cylinder, in-line gas or gasoline engine and a
7.5 KW(6.0 KW for 50 Hertz) alternating current
generator with standard or optional equipment as
ordered.
ENGINE
The JB engine has 60 cubic,inch (983.4 cm3) piston
displacement, 6.5:1 (9.2:1 for gas) compression ratio,
and is air-cooled. Basic measurements and other.
details are listed under SPEC/FICATlONS.
AC GENERATOR
The YO generatorsbeginning with Spec AA(Figure 1)
are four-pole, revolving field, brushless exciter
models of drip-proof construction. Generatordesign
includes both single and three-phase, 60 and 50 hertz
type generators. The generatorrotorconnectsdirect-
Iy to the engine crankshaft with a tapered shaft and
key. The generator is fastened to the engine by the
rotor-through,;,stud which passes through the rotor
shaft; it has a nut on the outside of the end bell: A
centrifugal blowerjon the front end of the rotor shaft,
circulates the generatorcooling airwhich is drawn in
through the end bell cover, over the rotor, and
discharged through an outlet at the blower end.
A ball bearing in theend bell supports theouterend of
the rotor shaft. The end bell and generator stator
housing, are attached byfour-through":studs which
'pass through the stator assembly to the engine-
generator adapter. The brushless exciter stator
mounts in the end bell while the excher rotor and its
rotating rectifier assemblies mount on the generator
rotor shaft.
The basic operation of the generator and voltage
regulator involves the stator, voltage regulator, ex-
citer field and armature, a full wave bridge rectifier,
and the generator rotor. Residual magnetism in the
generator r.otor and a permanent magnet embedded
in one exciter field pole begin the voltage build-up
process as the generator set starts running. Single-
phase AC voltage, taken from one of the stator
OVERALL LENGTH
BLOWER
TORQUE TO
130-150 FT. LBS.
(176-203 N. ~)
TORQUE TO
55-60 FT. LBS •.
(75-8 I Ne m)
IIIH!..---;.-- ROTOR-
THROUGH-STUD .
O-RING
, SEAL
ENGINE-
GENERATOR
ADAPTER.
ROTATING
RECTIFIER
ASSEMBLIES
ER
(HOUSED)
I$;~;;;;;;;;~~-;;;;Jf-- COVE R
LESS
R
STATOR
ROTOR
TO 35-38 FT. LBS.
(47-52 N. m)
FIGURE 1 •. GENERATOR (CUTAWAY VIEW)
:', -.-~.
4

8203
windings, is fed tothevoltageregulator as areference
voltage
for maintaining the generatoroutputvoltage.
The AC reference voltage'is converted to DC by a
silicon controlled rectifier bridge on the voltage
regulatorprinted
circuit board and fed intotheexciter
field windings. The exciter armature produces three-
phase AC voltage that
is converted· to DC by the
rotating rectifier assembly. The resultant DC voltage
excites the generator rotor winding to produce the
stator output voltage for the AC load.
The generator
rotor also produces AC voltage in the
charging winding of the stator which is converted
to
direct current for battery charging.
VOLTAGE REGULATOR
LOCATION
WIO
VOLTAGE
ADJUST
(OPTIONAL).
FIGURE 2. VOLTAGE REGULATOR ASSEMBLY
5
VOLTAGE REGULATOR
The line-voltage regulator on the J-series generator
sets
isan all solid state device; that is, no relays or
tubes are needed. Basic components of the voltage
regulator are:
• Printed circuit board
VR21
• Voltage reference transformer T21
• Commutating reactor CMR21
• Field circuit breaker CB21
• Voltage adjust rheostat R22 (Optional)
Figure 2 shows the above components
in a typical
control box,
on standard air-cooled electric.
generating sets.
CONTROLS
The standard control box has a battery charge rate
ammeter, a START-STOP switch, and field circuit
breaker on the control panel, Figure
3. Optional
controls that may be added on the housed units
or
separate boards include a fault lamp, a'frequency
meter, a running time meter,
an overspeed indicator, a
high temperature indicator, a volt adjust knob, a
phase selector, and
AC voltmeters.
. FIGURE 3. TYPICAL CONTROL PANEL.
FIELD
CIRCUIT
BREAKER
STADT .CT('P_-'
. SWITCH
DC
AM'1ETER
FAULT LAMP

The followingisa briefdescription of typicalcontrols
and instruments on the face of the panels; these may
vary according to the .customer requirements.
Standard
Remote Start-Stop Switch: Starts and stops the unit·
locally or from another location.
Oil Pressure Gauge: Indicates pressure of lubricating
oil in engine;unit located on the engine.
. Voltage Adjust .. Rheostat: Provides approximately
plus or minus 5 percent adjustment of the rated
output voltage (optional).
Optional.(On Housed Units)
AC Voltmete~: IndicatesAC generatorQutputvoltage. - .
Voltmeter Phase Selector Switch: Selects the phases
of the generator output to be measured by the AC
voltmeter. ; .
m
,.
Voltage ,AdJust Rheostat: Provides. approximately
plus or mint;J,s 5 percent adjustment of the rated
output voltage.
Running Time Meter: Registers the total number of
hours. t01110th that the unit has run. Use it to keep a
record for periodic servicing. Time is accumulative.
meter canno'llbe reset.
Frequency Me,ter:lndicates the frequency of the
generator ou~put in hertz. It can be u.sed to check
engine speed!; (Each hertz equals 30 rpm.)
Warning Llg~ts. Three red indicatoJ.lightsgive war ....
ningof: ';, ..
. . f, ..
- Overspeed~i'
-Low oil pr&ssure
-High engirtetemperature
~'''hr~e re~t:t~;~hptit*onsper"'i1,res~rtirig;.f:ter tr9u~ .'
;rcble IS cgr¥e~t~·., ·.f!·· ....
.,1'\
VOLTAGE RECONNECTION WITH .OP~~\
TIONAL INSTRUMENTS,
The optional AC.instruments on the- control panel .
(such as voltmeters and rUnning time meters) are
installed for use yvithspecj,fic nameplate voltages.
Control components may have to be changed Ja
match new current ratings when field reconnec.tion-
for other voltages are made!.
i ..
~ . '[0. prevent in~.rumenl damage, contac:,1 yC)ur
.'!' "':On8n Servi ler for requlredlnstrumlHlt
Cb.nges;Jnew:wlririg;Blsgrams, . er specification number, and
,'y,OItagebefore'attempting
to· re~nnect a .generator ;wlth in-
. ,:!tnime~b tii'e::e_~p .. et.:t"l: .;t~, .' ,-;',
',~.,. :i;J,,'~vef!:oads, 1;;
!I
"
6·

INSTALLATION
GENERAL
Installations must be considered individually,
however, the,following installation guidelines should
be followed. Installations' must conform to local
building codes, fireordinances, and otherlocal, state,
and federal regulations. See Figure
4.
Installation requirements include:
1. Level mounting surface.
2. Adequate cooling air ..
3. Adequate fresh induction air.
4. Discharge of circulated air.
5. Discharge of exhaust gases.
6. Electrical connections.
7. Fuel connections.
8. Accessibility for operation and servicing.
9. Vibration isolation.
10. Noise levels.
LOCATION
Provide a location that is protected from the weather
and is dry, clean, dust free and well ventilated.
If
practical, install inside a heated building for protec-
tion from extremes in weather conditions.
The air discharge side of set requires 3 inches
(76 mm) clearance from wall to permit set to rock on
its mounts; at least 24 inches (610 mm) clearance is
required around all othersidesforservice accessibili-
ty.
MOUNTING
A permanent type installation needs a sturdy, level,
mounting base
of concrete, a heavy wood or struc-
tural steel
at least 12 inches (305 mm)high to aid oil
changing and operating. Place the
7116 inch (11 mm)
mounting bolts
as shown in Figure 4.
Carefully assemble the mounting cushions, washers
and spacer bushing on the mounting bolts. The
spacer bushing prevents compression
of thesnubber
(upper rubber cushion). .
. ~. O. ne half inch clearance II required between
~olifllter and mounting bait to avoid punc-
turing filter.
For mobile applications (trucks or trailers) install
.slide-out rails
or someothermeans (such as doors) to
provide service space. See Figure 5.
VENTILATION AND COOLING
Air circulation is needed to dissipate heat produced
.
by the engine and generator iii normal operation.
Outdoor Installations (Figure 6) can rely on natural
circulation, but mobile, indoor or housed installations
need propersize and positioned vents for required air
flow, Figure
4. See SPECIFICA nONS for the air
requirements at 1800 rpm; . .
Vent sizes depend on variable conditions: (1) size
of
enclosure, (2) ambient temperature, (3) electrical
load,
(4) running time, (5) restrictions imposed by
screens, louvers, shutters,
or filters, and (6) preVailing
wind direction. .
A required volume of air mustreach the unit, absorb the heat, and
be discharged away from the installation.
Pressure cooled units need an inlet vent with an
unrestricted opening of at least 3-1/2 square feet
(3252
cm2) for variables. For discharged air, install
separate ducts from the engine and generator (see
exception)
as follows:
1. Theengine discharge duct must be the same size
.
as the engine outlet8 x 10inches (203 x 254 mm).
If a screen is used in the duct, increase the duct
size in proportion to the restriction. Consider
installing .the screen diagonally
to limit the
restriction and increase duct size
for runs over 9
fee~ (2.74 m). If bends are necessary, use large
radius elbows.
Usea canvas section.at the set to
absorb vibration and noise.
2. Generator outlet du~ts must be used when units
are installed in compartments
too smalJfo·r
operator
to walk. Ducts are recommended for all
other indoorinstallations. The air outlet is 5-5/8 x
3 inches (140 x
76 mm). Follow the same prin-
ciples of
duct design and installation as used for
the engine duct. Engine and generator require
separate ducts.
Vacu-.Flo Cooling Inlet Vent should be at least 1/3
square foot (309
cm2); the duct for discharged air
should be at least
as large as the scroll outlet. (See'
SPECIFICATlONS for airflow.)
Auxiliaryfans can be used to increase airflow tounits
installed in small, poorly ventilated
rOOmS. The fan
size and location should be such that the air inlet
to
.the engine doesn't exceed 120°F (49°C) when run-
ning at full rated
load~
I .WARNING , Utilizing eXhaul.t. heat to warm a room or
compartment occupied by people is not
recommended due to possible leakage of harmful exhaust gases.
EXHAUST GASES ARE DEADLY
POISONOUS!
7.

00
E
-~~~~=======~~ BOLT
( SQUARE NUT
E
~~~~~~~----LOCKWASHER
"l
~::::==-FLAT WASHER
SNUBBER
,~-r.I=NI=RATOR OR
01 L BASE MOUNTING
FOOT
_-(=u~,HION
--MuuWflNG SPACER
• BUSHING
SINGLE THIMBLE DIAMETER 12" (305 mm)
II" LARGER OR DOUBLE
~===i~'\="=d~ VENTILATED THIMBLE
DIAMETER 6" (152 mm)
LARGER THAN EXHAUST
·LlNE .
,1_
, 9"· 1\\"
, '
~
EXHAUST LINE PASSING THROUGH
WAU OR PARTITION'
DRAIN CONDENSATION TRAP
PERIODICALLY
A611
... 14,1516" --', '
(371 mm).
~E I . ~E' I-
Z
I I
: E 6.IJB (150 HERTZ) ~ S
,
~
I§ 7.6J. "" HERTZ) 1l:: •
+---.1
1.1.,5/8:: l
(295 mm)
fl:
~ 1,,·
5.0JB (50 HERTZ) ¥S
I-
~.
7,.~
Z
1
6.0JB (60
",:
HERTZ)
,01
u..
0 ~ ~
•
-.'-~--L
.
12,I/S"
.. 0
t,
I I
(308 mm)
E~
l-
6.0jB (SO HERTZ)
z
E ::::
7.5jB (60 HERTZ)
, 0
0'
-
0
+ ---J
N -
a:
u..
MOUNTING BOLT
LOCATIONS
LOUVER NEAR
AUTOMATIC
LOAD TRANSFER CEI LING ,,~~~~
INCOMING
SERVICE
CONTROL
'NOTE: IF REVOLVING FIELD TYPE
SET IS INSTALLED IN SMALLER THAN
APPROXIMATELY 384 ,CU. FT. (11m
3)
COMPARTMENT. DUCT GENE RATOR
HEATED AIR TO OUTSIDE.
DO NOT JOIN WITH DUCT FOR ENGINE
HEATED AIR.
FIGURE 4. TYPICAL INDOOR INSTALLATION
/
,/
THIMBLE

PLANT AND BATTERY MOUNTED ON
SLIDING TRAY FOR EASY ACCESS
FOR SERVICING
Provide openings near top of
compartment to permit heated
air to escape.
TRAY LOCK
FIGURE 5. TYPICAL MOBILE INSTALLATION
STAHDSY IH STAllATIOH
CONTROLS
ON THIS
END
-)\
. i ....
FIGURE 6. TYPICAL OUTDOOR INSTALLATION
9

EXHAUST
Vent exhaust gases outside.. Use flexible tubing
between the engine exhaust outletand rigid pipingto
accommodate vibration.
~WARNIN-G-) 'Check exhaust system frequently for leaks.
t...,; _ Be surepoisonous exhaustgases arepipedto
outside. Inhalation of exhaust gases can result
In serious personal
injury.
Shield'th.e line with fire retardant material. if it passes·
through a combustible wall
or partition. If turns are
necessary, use long sweeping type elbows. Use one
pipesize larger
for each ten feetin length. Position the
exhaust outlet away from the engine
air intake.
OIL DRAIN
Extend to suit installation. Oil base has a 1/2 inch
(12.7
mm) pipe tapped hole.
FUE.L TANK
If a separate fuel tank is used, install the tank so.the
bottom
is less than 8feet (2.5 m)belowthefuel pump.'
Thetank
topmustbe belowfuel pumplevel to prevent'
siphoning. Install a shut-offvalve at the tank. When
the fuel tank is shared with another engine; use a
separate fuel line
for each to avoid starving the set.
If fuel
lift must exceed 8 feet (2.5 m), install an
auxiliary electric fuel pump at the fael supply.
FUEL CONNECTION
Connect the fuel line to the fuel pump inlet. Pump is
threaded 7/16-24 NPTF (American Standard Internal
Tapered Pipe Thread)
..
I· WARNING ~ Always use flexible· tubing bet~een engine
'. • and the fuel supply to avoid line failure.and
fuel leaks due to
vibra~lon. Fuel leaks create tire and explosion
hazards.
For gaseous sets (see Figure 7), check with the local
fuel supplier
for gas regulations and line pressure.
Provide a manual gasvalve. A filter in the lirie may be
necessary. Electric solenoid shut-9ff valves in the
supply line are usually required
for indoor automatic
or remote starting installations. Connect solenoid
wires to .battery ignition circuit to open valve during
running. Install a demand type gas regulator accor-
ding to instructions and position it near theset to aid
starting.
WARNiNG] Always use flexible tubing between engine
Iw· _____ ._ and the gas demand regulator to avoid line
failure and leaks due to vibration. Gas-Gasoline sets provide a
manual shutoffvalve In both fuel supply ilnes. Fuelleakscreatefire
and explosion hazards. .
[!ARNING , Do not use galvanized lines, fittings, or fuel
tanks In underground portions
of the fuel
system. Hazardous fuel leaks may
be caused by· electrolytic
corrosion from moisture and chemicals In the soli (galvanism).
Some safety ordinances prohibitthe use
of galvanized materials In
fuel systems and the use
of threa.;j ,j cast Ironfittingsas well. Fuel .
leaks create fire and explosion hazards.
TO CONTROL
TERM· I
(GROUND)
TO CONTROL
TERM. 4
(PARALLEL WITH
IGNITION COl L)
A833
FIGURE 7. GAS FUEL LINE INSTALLATION
ELECTR.lCAl CONNECTIONS
The nameplate on the 'generator set shows the
electrical
output rating of thegeneratorin watts, volts, ..
and hertz.. The' wiring diagram, shipped with the
generator set, shows the electrical circuits and con-
nections needed during installation. .
All electrical connectionsshouldbedoneby aqualifiedserviceman
or electrician to meet the electricalcode requirementsin your area.
LOAD WIRES
The control box (junction box) has knock out sec-
tions to a:ccommodate load wires. Use flexibie con-
duit and stranded load wires near the set to.absorb
vibration. Use sufficiently large insulated wires.
Strip.
insulation from wire ends as necessary for clean
connections. Connect each load wire to the proper
generatoroutputlead insidethe setbox. Insulatebare
ends of ungrounded wires. Use
bolt provided on the
control box to connectthe generatorground lead and
load wire. Install a fused main switch (or circuit
breaker) between thegenerator and load. Ifatest-run
indicates wrong rotation of3phase motors
in the load
circuit, switch the connections at any two generator·
terminals.
Standby: If the installation is fOJ standby service,
install a double-throw transfer switch (either manual
or automatic type) to prevent feeding generator
output into the normal powersource lines and to also
preventcommercial powerand generator
output from
being connected to the load at the same time.
Instructions for connecting
an automatic load
transfer switch is included with such equipment.See
Figure
8.
Balance All loads: Divide the loads equally between'
output leads. Current loads for anyone output lead'
must not exceed nameplate rating.
10
1

LINE'
LOAD
GEN.
1
I -r"
L_______ JI
, --------
. NOTE: SHOWN WITH LINE CONNECTED TO LOAD.
FIGURE 8. LOAD TRANSFER SWITCH
~ ~verloading can damage the generator win-
~dmgs.
Single Phase Loads on Three Phase Generators: Any
combination
of single phase and three phase loading
can
be used atthesametime as long as thecurrent for
any output lead does not exceed the generator
nameplate rating.
Output Lead Markings: Leads on revolving field
generators are marked
T1, P, etc. Older models with
revolving armature generators had
output leads
marked
M1, M2, etc. These identifying marks also
appear on the wiring diagram.
SWITCHBOARD
Awall mounted switchboard containing ammeters, a
voltmeter, and
circuit breakers is optional. When
used, the following connections apply:
1. Connect one ungrounded (hot) generator lead to
the unused terminal on each ammeter.
2. Connect the generator lead and load wires which
are to
be grounded to the ground stud on the
switchboard.
3. Connect one ungrounded (hot) load wire to the
unused terminal on each
circuit breaker.
4. On sets that generate more than one voltage
(example: 120/240), the voltmeter should be
wired to indicate the higher
of the two voltages.
RECONNECTIBlE GENERATORS
The factory ships all special order sets with in-
struments on the control panels completely wired for
the voltage code or voltage specified on the
customers purchase order. Standard sets
without
instruments are shipped with the T'-P or T'-T'2
output leads separated in the output box. These
single phase and broad range generatorsare connec-
tible
or later reconnectible 'to provide any of the
output voltages shown in Figure 9.
Code 3C or 'S3C Reconnectlble Generators: The
single phase, 60 and 50 Hertz generators have
output
leads T1, P,P, and P available for making the single
phase voltage and load connections shown in Figure
9 at the installation site. Grounding procedu
re should
comply with local codes.
Code 18R
or 518R Reconnectible Generators: The
three phase, broad range,
60 and 50 Hertz 12 lead
generators have
output leads T' through T'2 available
for making several single and three phase voltage
load connections shown in Figure
9. Grounding
procedure should
comply with local codes.
When connecting the outputleads, be sure to connect lumperW10
on the voltage regulator printed
circuit board between terminal Y'
(common) and Y', Y', or y3 astlsted on thereconnection diagram ~
A broad range generator Is capable of generating numerous
different
output voltages as Indicatedbythe reconnection diagram.
Code 9X Generators: These special order three
phase, 60 Hertz, 4 wi
re, generatorsare prewired atthe
factory to provide 347/600 VAC.
Output leads T1, P,
P and TO are available for connection to the load
wi'res
.. See connection diagram. Grounding
procedure should
comply with local electrical codes.
BATTERY CHARGE RATE 'ADJUSTMENT
One generator wi'nding supplies current for the
battery charging circuit. The current flows to diode
CR", ammeter M", to the battery, and to the ignition-
fuel solenoid control circuits, Figure 10.
TO
CHARGING
1~~N~-"]
. RESISTOR
II
CHARGING CR II CONTRO~
R21
WINDING ,---+t-- -=-
-'V'./VV'\/'-----, S1 82
+111~
OC
~GENERATOR -
STATOR
CHARCING
RESISTOR --'--H--~~~
FIGURE 10. CHARGING RESISTOR

3C 12012..0
53C
120/2 ..0
18
518
I 151230
110/220
1201206
1271220
139/2 ..0
110'/190
1151200
1201208
1271220
18 ,2.. 0/ .. 16
25"/~0
277/ .. 80
518 220/380
18
518
2301400
2.. 0/ .. 16
25<4/ .. <40
120/2 ..0
110/220
I 151230
1201240
18 120/240
518 110~20
115/230
120/2 ..0'
18
120
518
110
115
.120
9X
3'17/600,
,B20('
3
3
3
l
3
3
l
3
3
3
3
3
3
,3
60
,50
5q
50
60
60
60
50
50
50
50
60
60
60
50
50
50
50
60
50
50
50
60
50
50
50
60
50
50
50
60
VI
V3
V2
VI
VI
V2
V ...
VI
V2
V3
V ...
VI
V2
V ...
Vi
V2
V3
V ...
VI
VI
V2
V3
VI
VI
V2
V3,
VI
VI
V2
V3
V4.
w
>"
~
...J
W
...J
...J
C
11:'
C
II.
w
>"
~
III
W
ii:
w
III
c
...
...J
W
o
III
W
II:
w
III
c
...
...J
W
o
W
...J
III
::::I
8
c
...
...J
W
o
...J
W
...J
...J
C
II:
C
II.
240
E
ILI
T2
1'3
T ..
L2
NOTE.: When instructed to connect V4to V4. either remove W10jumper or
insulate one end and leave unconnected.
GENERATOR CONNECTION
SCHEMATIC DIAGRAM
120
'[LI
T3 TI
if4T2
L2
LI
TI
Ll
T8
Til
T7
TIQ
T6
T3
L3
T2
T5
12 LO
9
LIT I L2
T" T5
T7 T I jr8' 2
TI~.;
LO""'-- Til
TiJ T9
T~I
L3
LI
~
12
T9' TI
L3 T6
1:3 T"
I-"-LO
Til T7
T8T _ TIO
T2
L2
,
~T: T:2 (~I .
~ LO
T9 TI2 T7
Til' .TIO
T8 '-Ll
LI
~
6
T
T9 Til TI T7
Til'
" 0"
TS
1'2
, L2
120/240
~
TI LI
T2
3 LO
iT" '
L2
LOAD TO
GENERATOR CONNECTION
WIRING OIAGRAM
CONNECT Xl TO VR21-5 FOR 50 HERTZ AND Xl
TO VR2l-6 FOR 60 HERTZ GENERATORS.
240 120 12,0/240
co AIAA lA '(
TI Tl T3 T~ TI T3 1:2 T~ TI ,Tl T3 n
A ~ A ~
T.. T5T6TIOTIITI2 TI T7 T2 T8 T3 T9
LO LI Ll L3
~ A A A
TIO Til Til TI T~ T7 Tl T5 T8 T3 T6 T9
T~T7 Tl,TIOT5T8 T3TII.T6T9 TITll
AA AA ~
Tl T~' T7 Til TI T6 T3 T5 T8 TIO T9 Til
LI Ll
A~~
TI'T7 T6 Til T3 T9T5 Til T~ TIO Tl T8
LI
Ll
L3
LO
LI
TI
Tl
LO
TI
Tl
T3
TO
FIGURE 9. GENERATOR WIRING AND C.ONNEC.TION DIAGRAMS
12

I
1. Theslidetap on adjustable resistor R21, located in
the generator air outlet, should be set .to give
about 2 amperes charging rate. For applications
requiring frequent starts, check battery charge
condition (specific gravity) periodically and if
necessary, increase charging rate slightly (slide
tap nearer ungrounded lead) until it keeps battery
charged. Having engine stopped when read-
justing avoids accidental shorts. Avoid
overcharging.
2. If charge winding AC output is below 19 volts on
12 volt battery charge models, test the charging
circuit for opens or grounds in the leads and
charging winding. If leads are defective, replace
them. If winding is defective, replace generator
stator. ..
3. Ifaseparateautomaticdemand control isused for
starting and stopping, adjust charge rate for·
maximum. 4.5 .amperes. This normally keeps
battery charged even if starts occur as often as 15
minutes apart. .
BATTERY CONNECTIONS
The battery is connected for negative (-) ground,
Figu re 11 .Be su re all batteryconnections are secu reo
BatterY polarity must agree with the rectifier located
in the control box. Ifbattery ground mustbe changed,
reverse the rectifier connection in the control box.
K"" STARTING MOTOR
STARTER
~~"""""".,;;...-
CRANKED
SETS
-
BATTERY
POSITIVE
12. V.BATTERY + ... I
- ~
I~
~
CABLE SIZE
2 0
00 000 0000
4 ft.
S .ft. 7
ft.
9 ft,
II ft~
14·ft.
FIGURE 11. BATTERY CONNECTIONS
~ If battery· polarity is reversed, damage will
L.-..';.~ occur within 3 minutes while stopped or 5
seconds
while running. Alternator windings will be damaged
almost instantly
if battery charging circuit Is shorted between
resistor
R21 and the B1 end of the charging winding.
See Specifications for minimum 12 volt battery re-
quirements. Connect battery positive (+) to starter
engaging solenoid terminal post, Figure 11. Connect
battery negative (-) to a good ground on the engine.
WIRE SIZE DISTANCE
#18
to 125 ft. (39 m)
#16
to. 200 ft. (62 m)
#14
to 300 ft. (93 m)
#12 to 500 ft.
(155m)
FIGURE 12. REMOTE SWITCH CONNECTIONS
REMOTE START -s..TOPSWITCH (OP-
TIONAL) .
For remote control sfartingand stopping, use3.,wires
to connect the remote switch (single pole, double
throw, momentary contact, center-off type) to the
terminal block marked Bot, 1, 2, 3,in the set control
box using vvire sizes as listed in Figu re 12.

OPERATION
PRE-STARTING
Preparations for the initial and each additional star-
ting operation should include careful checks of the
Oil, fuel, cooling,'and electrical systems. The cylinder
air housing door should be closed with all air sh muds
in place.
[ WARNING ~ Check exhaust system frequently forJeaks.
, ' " ! Be surepoisonousexhaustgases arepiped 10
outside. Inhalation of exhaust gasescan resulUn seriouspersonal
injury. '
Before generator set is put in operation, check all
components for mechanical security. If an abnormal
condition, defective part, or operating difficulty is
detected" repair or service as required. Thegenerator
set should be,kept free of dust, dirt, and spilled oil or
fuel. Be sure properoperating procedure is followed.
CRANKCASE OIL
Use a good quality heavy duty detergent oil that
meets the API (American Petroleum Institute)service
designationsMS, MS/DG,SE orSE/CC. Oil shou Id be
labeled as having passed the MS Sequence Tests
(also known as the ASTMG-IV Sequence Tests) and
the MIL-L-2104B Tests. Recommended SAE, oil
numbers for expected ambient temperatures are as
follows:
Above 32° F (0° C) ........................ SAE 30
O°F to 32°F (-1S0C to O°C) .... SAE 10W or 5W-30
Below 0° F (-1S0 C) ................... SAE 5W-30
When adding oil between oil changes, it is preferable
to use thesame brandasvarious brands of oil may not
be compatible when mixed together.
Do not use service OS oil. Do not mix brands or
grades. Refer to Maintenance section for recommend-
ed oil changes.
PRE-HEATER OPTIONAL
AIR
CLEANER
~~
,~
! '
RECOMMENDED FUEL
Use clean, fresh regular grade, automotive gasoline.
For new engines, most satisfactory results could be
obtained by using nonleaded gasoline. For older
engines that have previously used leaded gasoline,
heads mustbe taken offand all lead depOSits removed
from engine before switching to nonleaded gasoline. ,
~ If lead deposits are not r~moved from engine
~ before switching from leaded 10 nonleaded
gasoline, pre-ignition could
occur causing$eYeredamage to the
engine.
~ To avoid fire and ,explos, ion hazards, never fill
~ the tank when the engine is running. Leave
space in tank for expansion to avoid'overflow when fuelwarms up
to engine running temperature.
INITIAL START
Check the engine to make sure it has been filled with
oil and fuel. Cylinderairhousing door mustbe closed.
If enginefails to start at firstattempt, rust inhibitor oil
used atthe factory mayhave fouledthespark plugs
remove, clean in suitable solvent, dry thoroughly and
install. Heavy exhaust smoke when theengine is first
started is normal and is caused by the inhibitor oil.
Carburetor Air Preheater:Thecarburetorcombustion
air preheater (Figure13) directs engine warmed I;lirto
the carburetor when required to prevent carburetor
icing. The air inlet is automatically selected by the
Vernatherm (thermostatic element) which operates a
shutter in the induction airstream. Theshutteris fully
closed at SO°F (27° C),. is half open at90°F (32°C),
and is fully open to ambient air at 100°F (3S0 C).
8265-1
PRESSURE COOLED
VACUFLO COOLED
FIGURE 13. CARBURETOR PRE-HEATER
14

STARTING SEQUENCE
The starting and stopping (Figure 14) sequence
shows the manual, mechanical, and electrical events
required for satisfactory start, run and stop cycles.
STOPPING
1. Push start-stop switch to stop position.
2. Release switch when setstops.lf stop circuitfails,
close fuel valve.
APPLYING LOAD
If practicable, allow setto warm up beforecon.necting
a heavy load. Continuous generatoroverloadmg may
cause high operating temperatures that can damage
the windings. The generator can safely
h~ndle an
overload temporarily, but for normal operation, keep
the load within nameplate rating. Theexhaustsystem
may form carbon deposits during operation at
light
loads; apply full load occasionally befo~e shut-down
to prevent excessive carbon accumulations.
Try to connect the load in steps instead
of full load at
one time.' Most installations use a line switch that
must be closed
to connect a-portion of the load.
EXERCISE STANDBY PLANTS
Infrequent use results in hard starting .. Operate
standby sets at least
30 minutes each week. Run
longer if battery needs charging.
EMERGENCY OPERATION IF BATTERY
-FAILS
FIGURE 14. STARTING AND STOPPING SEQUENCE
STARTING
1. Push start-stop switch to start posi~ion.
2~ Release the switchafterenginestarts and reaches
speed.
3. Oil pressure gauge should read at least 20 psi
(138 kPa). Pressure relief is not adjustable.
If the set control has a reset button, push it to reset
only after a shutdown resulting from oil pressure
failure occurs. Find the cause before restarting the
engine.
To prevent fa.lse starts, hold on start switch until the centrifugal
switch automatically disengages starter motor.
~ Do not apply oyervoltage to the starting
.
circuit at any time. OYerv9ltage will destroy
the glow plugs and air heater In 2 to 3 seconds. If It becomes
necessary
to use an additional source of power to start the set - .
use a 12 Yolt battery connected In parallel.
If the battery fails completely and the set must be
operated during
an emergency, a battery can be
shared with otherequipment providing thesetcharg-
ing
circuit is disconnected.
BREAK-IN PROCEDURE
The unit should be run in the following sequence:
1. One half hour at 1/2 load.
2. One half hour at 3/4 load.
3. Full load.
Continuous running under one half load during the
first few hundred hours usually results in poorpiston
ring seating, causing higher than normal oil
con-
sumption and blowby.
Drain and replace the crankcase 011 after 50 hours of operation;
drain while the engine Is stili hot.
OUT -OF-SERVICE PROTECTION
To protect a set that will be out of service for more
than
30 days, proceed as follows:
1. Run set until thoroughly warm; generator under
at least
50 percent load.
2. Shut down engine and drain oil base while still
warm. Refill and attach a warning tag indicating
viscosity
of oil used.
3. Remove spark plugs. Pour 1-ounce (28 g) of rust
inhibitor (or SAE #10 oil) into each cylinder.
Crank engineoverseveral times. Install plugs.
15

. 4. Service ~ir cleaner. See maintenance schedule.
5. Clean throttle and governor linkage and protect
by wrapping with a clean cloth.
6. Plug exhaust outlets to prevent entrance of
moisture; bugs, dirt, etc.
7. Clean and wipeentire unit Coatpartssusceptible
to rust with a light coat
of grease or oil.·
B. Disconnectbattery and follow standard batte.ry
storage procedure.
'.
9. Provide a suitable cover for the entire unit.
Returning a Unit to Service.
1. Remove cover and .all protective wrapping.
Remove plug
from exhaust outlet.
2: Check warning tag on oil base and verify that oil .
viscosity
is .still correct for existing ambient
temperature.
'3. Clean and check battery. Measurespecificgravity
(1.260
at 77°F [25°C] ) and verify level to beat
split ring. If specific: gravity is low,charge until
correct value
is obtained. If level is low, add
distilled water and charge until specificgravity is
correct. DO
NOT OVERCHARGE.
. .
[. WARNING I Do not smoke while serviCing
. . batteries. Explosive gases are emitted
from batteries In operation. Ignition
of these gases can cause
severe peraonal Injury.
4. Check that fuel filter and fuel lines are secu re,
.with no leaks.
5. Check carburetor, adjust if necessary.
6. Connect batteries.
7; Verify that no loads are connected to generator.
8. Start engine.
After engine has started, excessive blue smoke will be
exhausted until the rust Inhibitor
or ollhasbumed ..away.
9 .. After start, apply load toatleast50 percent of
rated capacity.
10. Check al.1 gauges to be reading correctly. Unitis
ready for service.
HIGH TEMPERATURES
1; See thatnothing obstructsairfiow.toand from the'
set.
2. Keep cooling- fins clean. Air housing shoUld be
'... prope.rlyinstalled and undamaged.
LOW TEMPERATURES
1. Use correct SAE No. oil for temperature con-
ditions. Change oil only when ~ngineis warm. If
an unexpected temperature drop causes an
emergency, move the set to a warm location or
apply heated air (never use openflame) external-
ly until oil flows freely.
f~ .
2. Use fresh fuel. Protect against moisture conden-
satior). .
3. Keep fuel system clean, and batteries in a well
charged condition.
4. Check that fuel filter and fuel lines are secure,
. without leaks.
5. Check carburetor and adjust if necessary.
DUST AND DIRT
1. Keep set clean. K,eep cooling fins free of dirt, etc.
2. Service air cleaner as frequently as necessary.
3. Change crankcase oil every SO operating hours.
4. Keep oil and fuel in dust-tight containers.
S. Keep governor linkage clean.
HIGH AL°rlTUDE
Maximum .power will be reduced approximately 4
percent
for each 1000 feet (310 m) above sea level,
afterthe first 1000 feet (310 m). .
GAS-GASOLINE OPERATION
Engines having' a combination gas-gasoline car-
buretor can
be switched to gaSOline operation by the .
following procedure:
..
1. Close manual fuel.shutoff valve in supply line
(main fuel adjustment valve isnotdesignedtouse
as a shutoff valve) for gaseous fuel. ·Set will not
operate smoothly with both fuel supply lines
turned
on at the same time.
2. Open gasoline fuel shutoff valve.
3. Set spark plug gap at .025 inch (0.64mm).
4. See that choke is free and workseasily (be.sureto
release choke lock
on sets with electric choke).
5.Startengine.lfengine runsunevenly underhalfor
full load, due to faulty carburetor adjustment,
main Jet needs adjusting
..
To change back to gaseous fuel, reverse the above
procedure. Use all gasoline from the carburetor to
. avoid stale fuel;
If engine is run with one of the fuel
.
SUpply lines disconnected. plug other outlet to pre-
vent drawing
air and dirt into intake manifold.·
16

ADJUSTMENTS
CHECK BREAKER POINTS
Replace burned or faulty points. If only slightly
burned, dress smooth with file
or finestone. Measure
gap with thickness gauge, Figure
15.
1. The centrifugal switch is wide open when engine
is stopped. Loosen and move stationary contact
to correct gap.
2. Ignition breaker pOints mustbe correctlygapped.
Crank engine to fully open breaker pOints (1/4
turn after top center). Loosen and move
stationary contact
to correct the gap at full
separation. Tighten contact and recheck gap.
Ignition points should break contact justwhen timing
mark aligns
for degree of spark advance (orretard) as
specified. Final timing is corrected by properly
rotating the breakerplate at its mounting and using a
timing light.
If specified timing cannot beobtained by
rotati.on
of the breaker plate, check to be su re timing
marks on gears are aligned. Timing procedures
. appear
in separate service manual.
CARBURETOR (Gasoline)
The carburetor (Figure 16) has amain fuel (high
speed) adjustment(needle
A) and an idle fuel adjust-
ment (needle B). Early models have the main adjust-
ment needle on the top
of the carburetor. The main
adjustment (needle A) affects operation underheavy
load conditions. Idle adjustment affects operation at
light
or no load. Undernormal circumstances, factory
carburetor adjustments should
not be disturbed. If
the adjustments have been disturbed, turn needles
off
their seats 1 to 1-1/2 turns to permit starting, then
readjust them
for smooth operation. .
IGNITION
BREAKER POINTS
• 020'·'
FUEL IDLE
ADJUSTMENT
B
THIS DISTANCE
1/32 INCH AT NO LOAD
MAIN FUEL
PACKING NUT
ADJUSTMENT
~ NYLO: ROD EXTENDING
DOWN THROUGH LOWER
SHROUD
PAN.
FIGURE 16.. CARBURETOR ADJUSTMENTS
~ Loosen packing nut (Figure 16) before tur-
~ nlng main fuel adlustment and tighten to a
snug
fit afteradjustmenthasbeen made. Hold theadjustmentwhile
tightening packingnut.Thisprocedure
will make It easier to usethe .
carburetor adjusting tool (420-0169).
It will also prevent air entry
that causes
rough engineoperation and fuel leaks. The fuel leaks .
occur when the engine Is not. running and cause difficult starting
because the float level Is lowered.
~ Forcing the needle against its seat will
~ damage It. The needle does not completely
shut
off when turned fully in.
BEND TAB
TO ADJUST
ZENITH CARBURETOR
,0.913 Rev
THIS DIMENSI0I'o!.,
SHOU LD BE
1/8
(3.18 mm) FROM
GASKET
TO FLOAT
BOWL FLANGE
GASKET
FIGURE 15. BREAKER POINT ADJUSTMENT FIGURE
17. CARBURETOR FLOAT ADJUSTMENT
17

ADJUSTlMENT
GAS IDL~li
ADJUSTME~T
CLAMP 'I:
/ ADJI.JSTMENT SCREW
AMBIENT TEMPERATURE
(0 F) 75 70
60
50 40 30
20
10
CHOKE OPENING (Inches) 9/16 .' 1/2 15/32 7116 3/8 11/32 5/16 1/4
AMBIENT TEMPERATURE
(0 C) 24 21 16 10 4'
-1
.... 7 -12
CHOKE OPENING (mm)
14.~9
12.70 11.91 11.11
9.53 8.73 7.94 6.35
GAS~'AIN
GASOLINE IDLE
ADJUSTMENT
IDL'E SPEED
Before final adjustment, allow the engine to warmup.
Toset the
maiO fuel adjustment, applya full electrical
load to the generator, carefully turn main adjustment'·
screw in until':engine speed (or
output frequency)
drops slightly:beloW normal.
Tu.rn screw back out
(richer) approximately 1/4 turn or until engine speed
(frequency)
r~turns to normal.
Carbure'oradjus'men' 'should be made after 'he governor Is
properly adjusted.
Make idle adjustment with no load connected to the
generator.
Use a tachometer (orconnecta frequency'
meter) to generator output. Slowly turn idle adjusF
ment out
until engine speed (orgeneratorfrequency)
dropsslightly t?elownormal. Then turn needle
in until
speed (or frequency) returns to normal.
FIGURE 18. CARBURETOR ADJUSTMENTS
EARLY MODELS HAVE
MAIN FUEL
ADJUSTMENT ON
TOP OF CARBURETOR
GASOLINE
MAIN ADJUSTMENT
Set throttle stop screw (locatedon carburetorthrottle
lever)
with no load connected and while running at
rated speed. Turn stop screw to give
1132 inch
clearance between the screw and pin (Figure 16).
For correct carburetor float clearance, see Figure
17.
Adjustment is made by bending the tab on the float.
CARBURETOR (Gas-GasoUne) ,
Gas carburetor adjustment procedure is the same as
for gaSOline. See Figu re 18· for location of .adjusting
needles.
LOOSEN THIS
SCREW AND
ROTATE THE
ENTIRE eOVER
ASSEMBLY
,
FIGURE 19. CHOKE. ADJUSTMENT