Generac Power Systems TXP User Manual
F-
ALTERNATOR
DIAGNOSTIC REPAIR
MANUAL
%■
Printed in U.S.A.
GENERAC
P.O. Box 8, Waukesha, Wisconsin 53186
50357
Engine Air Cleaner
Conduit Clamp
Button Plug
(Optional location of conduit clamp)
Oil Dipstick
Blower Shroud
Vibration Dampener
POSITIVE Battery
Cable Connection
Starter Solenoid
Figure 1. NOMENCLATURE
I Customer Wiring Connection
—■ Access Panel
Main Circuit Breaker
15 amp Fuse
Start/Stop Switch
NEGATIVE Battery
Cable Connection
Solenoid Operated
Fuel Shutoff Valve
Lowo7L¡^'""®'
Shutdown Switch
Customer Fuel Supply
Line Connection
Fuel Pump
Oil Make Up Tank
(2 quart)
PART I
GENERAL
Section Title Page
1 Specifications.........................................................................................................................................................
Difference Data......................................................................................................................................................
Engine Lubrication................................................................................................................................................‘'■2
Electrical Test Specifications.............................................................................................................................. ■'•2
Torque Values........................................................................................................................................................‘'•2
Engine Specifications............................................................................................................................................
2 Wiring Diagram (Model 6931-0)............................................................................................................................2.1
Wiring Diagram......................................................................................................................................................2.2
Factory Equipped Customer Wiring Connections
TXP Reconnected for 120/240 Volt Output...........................................................................................................2.3
..........
...............................................................................
2.3
SPECIFICATIONS
Model No.
Wattage Capacity
Voltage Output
Amperes
Frequency
Phase(s)
Voltage Regulation
Driven Speed
Battery Charging
Amperes
Gross weight (wet)
Engine Type ■ ■
Engine Horsepower
Bore
Stroke
6931-0 6931-1 6931-2
4500
120/240*
37.5 at 120 Volts - 18.75 at 240 Volts
60 Hz
1-Phase
120 Volts ( + 27o) AC at 60 Hertz
1800 rpm
0-10 Amperes at 12 Volts DC
215 Pounds
2-Cylinder, 4-Cycle, Aluminum
Approximately 10 at 1800 rpm
3.44 Inches (87.3 mm)
2.16 Inches (54.7 mm)
Displacement
Valves
Stellite exhaust valves - Valve ro
tators on exhaust valves
40 Cu, In, (656 cc)
Governed Speed 1800 rpm
Air Cleaner
Crankcase Oil
Capacity
Oil Make-up System
Ignition System
Dry paper element, oil foam pre-cleaner
56 Ounces (3% Pints')
Maintains crankcase oil level at about
48 Ounces (3 Pints)
Solid state capacitor discharge type
Starting System 12 Volt DC electric (Ring Gear)
Cranking Current
Approximately 90 amperes nominal
*As shipped, alternator provides 120 volts AC only. Unit is
reconnectable to supply 120 and 240 volts AC. See Page 2,3.
DIFFERENCE DATA
Model 6931-0 - Rigid coupling between engine drive shaft and rotor
Model 6931-1 - Added a flexible coupling between engine drive shaft
___________________
and rotor
_________________________________________________________
Model 6931-2 t New rotor with improved 4-pole laminations. New im
proved blower housing with heavier sheet metal. New
_________________
improved inertia ring.with increased mass.
______________________________
Issued 6-78
1.1
ENGINE LUBRICATION
Use any high quality detergent oil
having a classification which inc
ludes ’’Service MS, SC, SD or SE”,
No special additives should be used.
ELECTRICAL TEST SPECIFICATIONS
RECOMMENDED SAE VISCOSITY GRADES
1 1
100
60
°C-30
TEMPERATURE RANGE ANTICIPATED BEFORE NEXT OIL CHANGE
-20 10 10
80
30 40
20
*If not available, a synthetic oil may be used
having — 5W-20, 5W-30 or 5W-40 viscosity.
COMPONENT
Stator Windings
AC Power Windings
AC Power Windings
Excitation Windings
Battery Charge
Windings
Rotor
Ignition Stator
Charge Coil
Trigger Coil
Ignition Stator Voltage
Input to Printed
Circuit Board
Fuel Pump DC Resistance
Spark Timing
Choke Heater
TEST POINTS
Wire #11 - Wire #22
Wire #33 - Wire #44
White receptacle Pin #2 -Pin #6,
Wire #55 - Ground
Wire #77 - Ground
Brush terminals or Slip Rings
Ignition Module Receptacle Pin
#2 - Ground
Ignition Module Receptacle Pin
#3 - Ground
PGB Pin #4 - Ground
Fuel Pump terminal to ground
Wire #77 - Ground
TEST VALUE
0,42 Ohms
0,42 Ohms
2,30 Ohms
0,20 Ohms
0, 20 Olmns
13,00 Ohms
225.00 Ohms 4
6,00 Ohms
0.5-1.5 Volts
50,00 Ohms
26 BTDG
30.00 ohms
Sensing Transformer
Secondary Winding
Primary Winding
Field Boost Voltage
(While Cranking)
Wire #11 - Wire #22
White receptacle Pin #3 - #5
White receptacle Pin #4 - Ground
NOTE;-Either of two transformer makes may be used. The Wescoil transformer
has a primary winding resistance of 745-825 Ohms and a secondary winding
resistance of 1603-2169 Ohms, The CoilTran transformer has a primary resis
tance of 824-1114 Ohms and a secondary resistance of 1222-1654 Ohms.
1.2
See NOTE
See NOTE
9 - 12 VDG
TORQUE VALUES
STANDARD TORQUE VALUES
Grade 2
BOLT SIZE
1/4-20 5 4
1/4-28
5/16-18 11 8
5/16-24
3/8-16
3/8-24 23 17 35
7/16-14
7/16-20
1/2-13
1/2-20 55 42
9/16-12
9/16-18 78
5/8-11
5/8-18
3/4-10
3/4-16
DRY LUB
6 5 10 7 12
13 10
20
32
36
49
70
92
105
165 125
180
1525
27
38
54 110 84
60 120
71
81
140 295
All Values in FOOT-POUNDS
TORQUE VALUES + 5 PER CENT
DRY
17 13 21
19 15 24
31
49 38
55
75
85 65 105
150
170
270 205
Grad
8
----------
LUB DRY
6
24
27
42
58
93 150 115
115 185 145
130 210 160
230
Grade 7
LUB
10
16
18
38 29
43
61
68
93 - 72
135 105
330
365
33
47
52 78
■ 80
250
280
Grade 8
DRY
8
9
27
49
105
120 90
155
170 132
210 165
240 185
375
420 320
■ LUB
12 9
14
24 18
44
70
11
21
34
38
54
60
82
120
290
7/8-9 200
7/8-14
1-8
1-14^ 340 260 680
SPECIAL TORQUES
Connecting Rod.
Cylinder Head (Torque in staggered.sequence)
Spark Plug.:.
Starter Motor Mounting Bolts..,i.............................................. .........................................160 In.-Lbs.
Engine Base
Sump (7 bolts)....
Crankcase Cover (7 bolts).
Governor Lever Lock Nut...,.
Fan to Engine Shaft Capscrew (Grade 5)-(Apply Loc^Tite
601 to capscrew threads:)
Flex Coupling to Rotor Hub Capscrews (Model 6931-2) -
(Apply LocTite 601 to capscrew, threads)................................................................. 19 Ft.-Lbs.
Flex Coupling to Fan Capscrews (Model 6931-2) - (Apply
LocTite 601 to capscrew threads).....................................................................................
.........
.....................................................................................................................
..............................
225 170 435 335
300
GRADE
BOLT HEAD
SYMBOL
.........
................................................ 200 In. -Lbs.
155 395 305 530
585 450
230
590 455
510
795 610
O
.
........................................................................••..190 In.-Lbs.
..................................
.(......I-............................................. 160 In.-Lbs.
.............................................................................
...........................................................................................
..................
..........
......................................................... 19 Ft.-Lbs.
..........
405
©
............
.......140 In.-Lbs.
605
670 515
905 695
..160 In.-Lbs.
300 In.-Lbs.
100 In.-Lbs.
19 Ft.-Lbs.
455
Issued 6-78 1»3
ENGINE SPECIFICATIONS
Spark Plug Gap
Crankshaft End Play..
Governed Idle Speed Adjustment...............................................................................................
Valve Clearance (with springs installed)................................................................Intake .005"-. 007"
Valve Seat Angle...........................................................................................................Intake - .30
Valve Seat.Width...............................................................................................
Valve Seat Margin................................................................................................Not less than 1/64'
Valve Clearance (springs not installed).,......
Crankshaft Reject Sizes.........................................................................................PTO Journal 1.376'
Cylinder Boi'e Standard Diameter
Ring Gap Reject Sizes (Top and center compression)......................................................................0.035'
Ring to Ring Groove Maximum Clearance
Maximum Piston Pin Out-of-Roundness....................................................................................,0,0005'
Crankpin Bearing Hole Rejection Size........................................................................................
Piston Pin Bearing Hole Rejection Size...;,.......................................................,,,,.,.,,.....0,802'
Camshaft Rejection Sizes (Gear and. Shaft Journals).......................................................................0,623'
Cylinder Bore Maximum Out-of-Roundness,
Cylinder Bore Oversizes when honing..........................................................
..................................................................................................................................
.............................................................................................
.........................................................
...................................................................................
(oil Ring)................................................................................ .......0.045'
........................................................................................
(Cam Lobes)
.........................................................................
.........................................................................0,0025'
........
0.002"-0.008"
1400 rpm*
Exhaust .007"-.009"
Exhaust - 45
...................
Intake .007"-.009'
0,010" above standard
0.020" above standard
0.030" above standard
3/64"- 1/16’
Exhaust ,009"-.Oil'
Crankpins 1.622'
..... 3.4375**
...1.252'
0.030"
0.007'
1.124'
*Adjust carburetor idle screw to 900 rpm
**Resize if worn 0.003" or more
1.4
Issued 6-78
CM
(O
s
<
oc
(3
<
o
CD
z
SCHEMATIC
tH
I
CNJ
WIRING DIAGRAM
E
MODEL 6931 -0
legend
CH~ cnoke So/enold
CB— Circuit Breaker
D— Diode
PP— Fuel. Pump
FS— Fuel Solenoid
HM— Hour Meter
IM— Ignition Module
IS— Ignition Stator
UT— Light
LOS— Low Oil Switch
FCB— Printec? Circuit Board
S— Starter
SC— Starter Solenoid
SW— Start-Stop Switch
T— Transformer
SP— Spark Plug
VR— Voltage/Frequency Regulator
^ — Wire Nut
WIRING DIAGRAM
00
CO
X)
0)
. d
CO
CO
I
ro
to
WIRING DIAGRAM
W
in
0
0)
a-
OJ
■o
oo
I
MODEL 6931-1
6931-2
)
),
Factory Equipped Customer Wiring Connections
120VoitsOniy
PROCEDURE
1. Disconnect wires No. 11 and No. 33 at
main circuit breaker,
2. Disconnect wire No. Ti at main cir
cuit breaker and discard.
3. Route wires No. 11 and 33 (discon
nected from main circuit breaker) to
customer connection panel.
4. Connect customer wiring as shown
to obtain both 120 and 240 volts A-C.
XR
Main
Circuit
Breaker
Main Circuit Breaker is Not Connected
TXP RECONNECTED FOR 120/240 VOLT OUTPUT
Issued 3-78
Grounding Lug
PART II
TROUBLE DIAGNOSIS
Section Title Page
3 DIAGNOSTIC FLOW CHARTS
Engine Won’t Crank....................................................................................................................3.1
Engine Cranks, Won’t Start.........................................................................................................3.2
Engine Starts Hard, Runs Rough............................................................................................... 3.5
Switch Set to STOP, Engine Keeps Running..............................................................................3.7
A-C Voltage Low..........................................................................................................................3.8
A-C Power Low............................................................................................................................3.9
A-C Voltage High.........................................................................................................................3.9
No A-C Voltage..........................................................................................................................3.10
4 DIAGNOSTIC TESTS
Test 1-15 Amp Fuse..................................................................................................................4.1
Test 2 - Battery............................................................................................................................4.1
Test 3 - Start/Stop Switch............................................................................................................4.2
Test 4 - Starter Solenoid
Test 5 • Starter Motor...................................................................................................................4.4
Test 6 - Starter Bendix Gear........................................................................................................4.4
Test 7 - Starter Ring Gear............................................................................................................4.5
Test 8 - Check Spark...................................................................................................................4.5
Test 9 - Oil Make-up Tank...........................................................................................................4.6
Test 10 - Low Oil Switch..............................................................................................................4.6
Test 11 - Spark Plug....................................................................................................................4.7
Test 12 - Ignition Module.............................................................................................................4.7
Test 13 - Ignition Stator................................................................................................................4.8
Test 14 - ignition Coil...................................................................................................................4.8
Test 15 - Low Fuel Level..............................................................................................................4.9
Test 16 - No Fuel Flow...............................................................................................................4.10
Test 17 - 4 Amp Fuse.................................................................................................................4.10
Test 18 - Printed Circuit Board....................................................................................................4.11
Test 19- Fuel Filter.....................................................................................................................4.11
Test 20 - Fuel Shutoff Solenoid.................................................................................................4.12
Test 21 - Fuel Pump...................................................................................................................4.12
Test 22 - Check Installation........................................................................................................4.13
Test 23 - Carburetor...................................................................................................................4.14
Test 24 - Compression...............................................................................................................4.15
Test 25 - Head Gasket...............................................................................................................4.15
Test 26 - Valves.........................................................................................................................4.15
Test 27 - Rings...........................................................................................................................4.15
Test 28 - Cylinder.......................................................................................................................4.15
Test 30 - Choke..........................................................................................................................4.16
Test 31 - Pre-Choke...................................................................................................................4.17
Test 32 - Governor.....................................................................................................................4.17
Test 33 - Frequency...................................................................................................................4.18
Test 34 - Excitation Windings.....................................................................................................4.19
Test 35 - Carbon Buildup...........................................................................................................4.19
Test 36 - Cutput Voltage............................................................................................................4.19
Test 37 - Sensing Transformer
Test 38 - Main Circuit Breaker...................................................................................................4.21
Test 39 - Rotor...........................................................................................................................4.21
Test 40 - Field Boost..................................................................................................................4.22
Test 41 - Stator...........................................................................................................................4.23
Test 42 - Charging Cutput..........................................................................................................4.23
Test 43 - Circuit Breaker........................................................................................................... 4.24
Test 44 - Diodes D1 and D2.......................................................................................................4.24
Test 45 - Stator Battery Charge Windings..................................................................................4.25
................................
..................................................................................................
'..............................................................................4.3
4.20
DIAGNOSTIG FLOW CHARTS 3
IMTRODUCTION
Use these FLOW CHARTS in conjunction with the detailed instructions for
each test in Section 4, Test numbers assigned In the FLOW CHART are id
entical to the test numbers assigned to specific tests in Section 4.
ENGINE WON’T CRANK
TEST 1 Page
15 Amp
Fuse
-------1-------
CHECKS
BAD
f
Replace
Fuse
TEST 6
Starter
Bendix
Gear
«i^'^Retalner
Pin
Gear
CHECKS
BAD
t
Replace
Bendix
Gear
CHECKS'
GOOD
Page
4.4
Clutch
4.1
CHECKS
GOOD
CHECKS
■ GOOD
Test 7
Starter
Ring Gear
TEST 2 Page
Battery
4.1
■ CHECKS
GOOD
CHECKS
BAD
Recharge or
Replace
TEST 5 Page
STARTER
4.4
MOTOR
CHECKS
TEST 4
Starter
Solenoid
GOOD
CHECKS
CHECKS
BAD
1
Replace Replace
Motor
Solenoid
Page
4.5
CHECKS
GOOD
BAD
t
TEST 3
Page
4.3
Start/Stop
Switch
CHECKS
BAD
Replace
Switch
^CHECKS
GOOD
Paee
4.2
Issued 3-78
CHECKS
BAD
3.1
ENGINE CRANKS , WON’T START
TEST 8 Page
Check
Spark
TEST 13
Ignition
Stator
4.5
Page
4.8
NO
SPARK
•GOOD-
TEST 9
Oil
Make-Up
Tank
TEST 12
Ignition
Module
LOW
FILL
TANK
Page
4.6
—GOOD
4.7
-------
-GOOD-
TEST 10
Low Oil
Switch 4.6
Page
4
BAD
I
REPAIR/
REPLACE
TEST 11
Spark
Plug
Page
4.7
GOOD
BAD
__L
Replace
Stator
TEST 14
Ignition
Coil
GOOD
BAD
BAD
I
Replace
Module
[Replace
Coil
^jlF SPARK CHECKS GOOD,«
^ GO TO TEST 15 3
BAD
Replace
Plug
3.2
Issued 3-78
______________________
TEST 15
Low Fuel
Level
.
To Vthicii
Engintf
Page
To Alternitor
Engine
4.9
— GOOD
TEST 16
No Fuel
Flow
Page
4.10
-BAD
TEST 17
4 Amp
Fuse
Page
4.10
___________
TEST 20
Fuel
Shutoff
Solenoid
Fuel ^
T«ik В
FILL
TANK
S ^‘Pe
Д Nipple
^<^Anti ■ Siphon
Holes
LOW
i
Page
4.12
Pipe Cep
■GOOD.
TEST 19
Fuel
Filter
”F“
GOOD
GO TO
TEST 23
Page
4.11
-.GOOD
BAD
I
REPLACE
FUSE
TEST 18
Printed
Circuit
Board
и ~ c=3 p|n
GOOD
Page
4.11
GOOD
REPLACE
SOLENOID
TEST 21
Fuel
Pump
BAD
Page.
4.12
GOOD.
■ BAD-
------------------
TEST 22
Check
Installation
,| REPLACE
BAD
REPLACE
FILTER
PUMP
1
—I—
BAD
REPLACE
BOARD
Page
4.13
SIF TEST 1.6 IS GOOD,t
3 GO TO TEST 23 (
Issued 3-18 3.3
TEST 23
Carburetor
J / ^
Page
4.14
TEST 24
COMPRESSION
Page
4.15
BAD
TEST
GOOD
REPLACE
GASKET
ADJUST
JETS
’
FLOAT
SEAT
FLOAT
LEVEL [
-BAD J replace
|. SEAT
1
hBAD-
NO
■ CHANGE’
I adjust"
'I FLOAT.
-8^,TEST
REPIACE
CARBURETOR
TEST
,1 TEST
BAD
1 TEST
TEST 26
VALVES
1
-------
TEST.
TEST 28
CYLINDER t4.15
1 REPAIR 1
_Page_
Page
4.15
3.4
T.EST.
TEST 27
RINGS
h:
Page
4.15
REPLACE I
GOOD
■ GOOD
GOOD
-»‘I GO TO TEST 29§i
_ - --
_ - .
Issued 3-78
ENGINE STARTS HARD - RUNS ROUGH
Issued 6-78
3.5
TEST 15.
Low Fuel
Level
Page
4.9
■ GOOD
TEST 16 Page
Fuel Flow
4.10
BAD
-GOOD-
TEST 23
Carburetor
Page
4.14
TEST-^
TEST-*-
FILL
TANK
REPLACE
FILTER
REPLACE
SOLENOID
TEST 19
Fuel
Filter
TEST 20
Fuel
Shutoff
Solenoid
Page
4.11
9
[adjustI
Ijets
BAD^
REPLACE
CARBURETOR
-TEST
CHECK
REPLACE
SEAT
-TEST
Page
FLOAT
VALVE
■ BAD*.
4.12
ADJUST
FLOAT
-TEST,
1 ■
FLOAT
LEVEL BAD-^
TEST-*-
3.6
REPLACE
PUMP
TEST 21
Fuel
Pump
TEST 22
check
Installation
Pagè
4.12
Page
4.13
TEST 32
Gove mor
"^8 COMPRESSION "
Page
4.17
’change'
BAD
I
ADJUST
GOVERNOR
5 GO TO TEST 24 I
Issued 3-78
NO
TEST 24
Compression
-—BAD
TEST 25 .
Head Gasket
Page
4,15
TEST 26
Valves
Page
4.15
BAD
REFI ACE
GASKET
TEST
GOOD-
TEST 27
Rings
REELAGEl
R-INGS
BAD
GOOD
REPAIR
''
TEST
Page
4.15
BAD
1
Issued 6-78
TEST.
SWITCH SET TO STOP - ENGINE KEEPS RUNNING
TEST 3
Start/Stop
Switch
Page
4.2
-BAD
I REPLACE
■ *" SWITCH
3.7
A-C VOLTAGE LOW
TEST 33
Check
Frequency
BAD
TEST 32 Page
Governor
Page
4.18
4.17
■ GOOD
¡testI
REPLACE
STATOR
■ GOOD-
REPLACE VOLTAGE
REGULATOR
3.8
Issued 6-7 8
A-C POWER LOW
GOOD
T
TEST
NO .
■ CHANGE'
TEST 35
Page
Carbon
Build-up
.4.19
DE-CARBONIZE
- HEAD
TEST
NO
CHANGE
NO ‘
-CHANGE-
TEST 32
Governor
(^
Page
4.17
sf^ ^
TEST
A-C VOLTAGE HIGH
NO A-C voltage,
TEST 36
Page
Cheek
Output
4.19
Voltage
GOOD
I
CHECK CUSTOMER
WIRING
TEST
TEST 38
Main
Circuit
Breaker
BAD
REPLACE
CIRCUIT
BREAKER
~T~
TEST
Page
TEST 29
Rotor
Page
4.21
4.21
-GOOD■
BAD.
I
REPLACE
ROTOR
TEST
GOOD
TEST 41
Stator
REPLACE
STATOR
TEST.
Page
4.23
GOOD
CHECK WIRE
#14 '
[testI-
-BAD.
CHECK VOLTAGE
TO ROTOR
------------1------------BAD
_L_
CHECK #4 WIRE
FOR 12 VOLTS'
-----------
1
----------------
GOOD
I
REPLACE
PRINTED
CIRCUIT
BOARD
3.10
Issued 3-78
DIAGNOSTIC TESTS
TEST 1 - l.S.AMP -FUSE
Remove and visually inspect the 15
amp fuse. A more thorough check may
be made with a Volt-Ohm-Milliammeter,
a_s foil o\vs :
1. Set VOM to ''+nC" and to ”Rxl”
scale.
2. Connect test probes together and
’’Zero" the meter.
3. Touch test probes to the fuse
ends - meter needle should swing up
scale and indicate "Zero” ohms. If
needle does not move upscale, replace
the fuse.
RESULTS: 1.) Fuse tests bad.............Install new 15 Amp Fuse
2.) Fuse tests good
...............................
.....Continue tests in "Diagnostic
4
Flow Charts", Section 3
TEST 2 - BATTERY
Check battery condition, as well as
the condition, cleanliness and sec
urity of battery cables and.connec
tions.
RESULTS: 1.) Battery, cables or connections
test bad.......................................
2.) Battery, cables and connections
test good
..................................................
.....Replace or repair the defec
tive component
Continue tests in "Diagnostic
Flow Charts", Section 3
Issued 3-78
4.1
TEST 3 -START - STOP SWITCH
/^5
Remove the 15 amp Fuse to disconn
ect the starting circuit. Then re
move 2 screws that retain the top
panel. Finally, remove the top
panel.
RESULTS: 1.) Switch tests Bad..
2.) Switch tests Good.
Connect the VOM test probes to the
Switch terminals as shown at right.
Hold Start./Stop Switch at START meter needle should not move.
Set the switches of a Volt-Ohm-
Milliammeter to and to ''Rxl"
scale. Connect meter test probes
together and ”Zero" the meter.
Connect the meter test.probes to
the switch center and lower termi
nals, as shown above. Meter needle
should not move. Hold Switch at
STA.RT position - meter needle
should, move upscale, to "zero”.
Hold switch at STOP - meter needle
should drop all the way downscale
to "Infinity”.
.
......................
......................
Install a new switch
Continue tests
Release the Switch to NEUTRAL po
sition - the meter needle, should
not move.
Hold the Switch at STOP - the. meter
needle should swing upscale and. ind'
icate "zero" ohms.
RESULTS: 1.) Switch tests Bad..
2.) Switch tests Good.
4.2
.Install a new Sta.rt/Stop Switch
.Reconnect wires to Switch
Install top panel
Install 15 Amp Fuse
Continue Tests
Issued 3-78
TES T 4 - STARTER SOLENOID
A.) Set the Start/Stop Switch to
START position and back to NEUTRAL
several times. An audible "click”
should be heard as the solenoid
actuates^
RESULTS: !.) Solenoid actuates, but
engine does not crank
...............................
Continue- ttst (Paragraph "B")
2.) Solenoid does not actuate,..Continue test (Paragraph "D")
B. ) Set VOM to "+DC" and to a scale greater than 12 Volts DC. Connect
the NEGATIVE (pr COMMON) test probe to. ground. Connect the POSITIVE (+)
test probe to the battery cable connection on the starter solenoid. The
meter needle should indicate 12 volts DC.
RESULTS: 1.) Meter reads 12 VoltsContinue test (Paragraph "C")
2.) Meter indicates less
than 12 Volts..............................................Check for open or shorted wire
or loose connections between
battery and starter solenoid
C. ) Connect POSITIVE (+) meter probe to starter cable connection on
starter solenoid. Connect NEGATIVE (or COMMON) test probe to ground.
Hold Start/Stop Switch at START - meter should indicate 12 volts DC.
RESULTS: 1.) Meter does not indicate
12 Volts...............................................
..Install new starter solenoid
2.) Meter reads 12 Volts and
solenoid checks good.......Continue tests in "Diagnostic
Flow Charts", Section 3
D. ) Set VOM to "+DC" so that 12 Volts can be read. Connect, meter POS
ITIVE (+) probe to one of the small terminals on the starter solenoid.
Connect the remaining test probe to ground. Meter should read.12. Volts.
With NEGATIVE (or COMMON) test probe still connected to ground, conn
ect POSITIVE (+) test probe to the other small terminal. Meter should
indicate 12 volts DC.
RESULTS.: 1.) Meter indicates 12. Volts
from BOTH small terminals
to ground
.............
Continue tests in. "Diagnostic
Flow Charts", Section 3
Meter does NOT read 12
2.)
Volts.........................................................Retest battery, 15 Amp Fuse
and Start/Stop Switch. Wlien
sure that these components
are good, and 12 volts is not
obtained from both small ter
minals, replace solenoid,
Issued 3-78
4.3
TEST 5 - STARTED MOTOR
A.) Set VOM to ”+DC" and to a high
enough DC volts scale to permit
reading 12 volts. Connect the POS
ITIVE test probe to starter cable
connection at the starter. Connect
the NEGATIVE (or COMMON) test lead
to ground,then hold Start/Stop
Switch at START. Starter should
run and meter should read 12 Volts.
RESULTS: 1.) Meter, indicates .12.. Volts,
■ but starter does not run...... Replace starter
2.) Starter runs........................................................Continue tests in "Diagnostic
Flow Charts", Section 3
RESULTS: 1.) Starter motor can be heard
running without load,
L'OOCAOOOOO .Continue checks in Paragraph
IfRtt
'B
2.) Starter runs and cranks the
engine
.....................................................
...Continue tests in. "Diagnostic
Flow Charts", Section 3
B. ) Remove starter. Inspect pinion gear for damage or excessive wear,
RESULTS: 1.) Starter pinion gear damaged,
..................................................
2.) Starter Pinion gear is good,.................................................Continue test (Para
C. ) Without installing starter, connect starter cable from starter sol
enoid to starter terminal post. Hold Start/Stop Switch at START. The
starter pinion gear should move outward on the clutch.
4.4
Replace
graph C)
Issued 3-78
RESULTS: 1.) Starter Pinion Gear does
not move outward.............................
2.) Pinion Gear does move out
ward.’
..................................................
TEST 7 - STARTER RING GEAR
A.) Inspect Starter Ring Gear for
damaged teeth.
.
.
Inspect helix on clutch for
freedom of operation. If
sticking due to dirt, clean
entire starter drive. If
any parts are damaged or
worn, replace.
.Continue tests in ’’Diagnos
tic Flow Charts", Section 3
RESULT: 1.^ Ring. Gear damaged,
2.) Ring Gear Good....
TEST 8 -CHECK SPARK
A.) Remove lead from one spark plug.
Connect the lead to Spark Plug test-
er,
plug tester clamp to a clean, paint-
free ground. Crank the engine - a
sharp, "snappy" spark should be seen.
Repeat the test for the remaining
spark plug. _______________________
NEVER crank the engine, with a spark
plug or spark plug lead removed, un
less the spark plug or.lead Is conn
ected to a clean ground. Failure to
ground the plug or lead can damag.e.
the ignition coil. _______________________________
Part No. 41503. Attach the spark
^CAUTION
.Replace
.Continue tests in "Diagnostic
Flow Chart", Section 3
RESULT: 1,)A sharp, snappy spark is NOT
observed...
2.)A sharp, snappy spark is ob
served.
........
...........................................
.....
..................................................
Issued 3-78
.Continue tests in "Diagnostic
Flow Charts", Section 3
.Continue tests in "Diagnostic
Flow Charts", Section 3 4^5
TEST 9 -OIL MAKE-UP TANK
A.) Check Oil level in Oil Make-up
Tank. If oil level is near OIL
CHANGE LEVEL arrows, refill tank
with same, type and grade of oil
used in engine crankcase.
RESULTS: 1.) Oil level LOW..
2.) Oil level.GOOD.
TEST 10 - LOW OIL SWITCH
A.) Remove one screw that retains the Low Oil Switch Cover. Move Cover
out of the way.
Set VOM to "+DC" and to "Rxl" scale. Connect meter test probes and zero
the meter. Connect one meter test probe to lower left switch terminal
and remaining probe to ground terminal (bottom of switch). With switch
actuating lever DOWN (low oil condition), meter needle should swing up
scale to "Zero". If meter
A.) Remove one screw that retains the Low Oil Switch Cover. Move Cover
out of the way to.expose switch terminals.
Set VOM to "+DC" and to "Rxl"
scale. Connect meter test probes
and "zero" thé meter. Connect
one test probe to lower left
switch terminal. Connect remain
ing test probe to ground. With
switch actuating lever DOWN (low
oil level), meter needle should
swing upscale to "zero". With
switch actuating lever UP (norm
al oil level), meter needle should
drop all the way downscale to
"infinity". MAKE SURE GROUND WIRE
BETWEEN SWITCH BOTTOM TERMINAL AND OIL FILLER. NECK BRACKET SCREW IS
TIGHT.
.Refill tank
.Continue tests in "Diagnostic
Flow Charts", Section 3
4.» 6
Issued 3-78
CAUTION
Before installing Low Oil Switch Cover, make sure the float arm is
riding on top of the switch actuating lever. If float arm has dropped
off of switch actuating lever, engine will not shut down when oil
level in tank is low.
RESULTS:.!.) Switch tests Bad
2.) Switch tests.Good...............Continue tests in "Diag
TEST 11 -SPARK PLUG
A,) Remove one spark plug. Connect
spark plug wire to plug. Ground
spark plug against engine. Hold
Start/Stop Switch at START and ob
serve spark plug. A sharp, snappy
spark should be seen. Repeat test
for second spark plug.
CAUTION
NEVER crank engine with a spark
plug or spark plug wire removed,
unless the spark plug or wire is
connected to a clean ground.
Failure to ground the plug or
lead can damage the Ignition coil,
............................................................
Replace Switch
nostic Flow Charts", Sec
tion 3
RESULTS: 1.) Sharp, snappy spark is
NOT observed.
2.) Sharp, snappy spark IS
observed,.
Test 12 - IGNITION MODULE “
A.) Unplug the Ignition Module
from its receptacle. Inspect the
connector pins in the module and
module receptacle - make sure
the pins are not bent or pushed
in. Install a new (or "shop") ig
nition module and check for norm
al spark.
RESULTS: 1.) Normal "hot" sparking...................................................Install a new Ignition
2.) Normal sparking NOT observed.... Continue tests in"Diagnos-
.........
....
........................................
......
.................................................................. .Continue tests in
.Replace spark plug
"Diagnostic* Flow
Charts", Section 3
Module, continue tests
tic Flow Charts", Section 3
Issued 3-78
Loading...