Yamaha EF1000iS Service Manual

							5-7
IGNITION SYSTEMELEC
7. Oil level switch
9Remove the oil level switch from the bottom
of the crankcase.
Refer to “CRANKSHAFT2, CAMSHAFT
AND ROCKER ARM” in CHAPTER 3.
9Connect the pocket tester to the oil level
switch for continuity.
Tester (+) lead →Blue lead 1
Tester (–) lead →Ground 2
1 212
å∫
å å
Continuity →Correct
∫ ∫
No continuity →Correct
8. Wire harness
9Check the terminal of the connector for con-
tamination, rust, or disconnection.
Replace the speed limiter.
Replace the TCI unit.
*
Replace the oil level switch.NO CONTINUITYCONTINUITY
Correct or replace the connector.NO GOODGOOD
GOOD
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							5-8
GENERATOR SYSTEMELEC
GENERATOR SYSTEM
TROUBLESHOOTING CHART
WEAK OR NO AC CURRENT
Start the engine.
Check the overload warning light.
DOES NOT TURN ON TURNS ON
Start the engine.
Check the pilot light.
DOES NOT TURN ON TURNS ON
Rated engine speed inspection.
9Operate the engine with no load.
9Set the economy switch to “OFF”.
5,000 r/min
GOOD OUT OF SPECIFICATION
Check the overload warning light.
TURNS ON DOES NOT TURN ON
Check the pilot light.
Check the throttle control system.
Refer to “THROTTLE CONTROL SYSTEM” in
CHAPTER 6.
AC coil 1 AC voltage inspection
9Connect Brown-Green (R-S), Green-Brown (S-T),
and Brown-Brown (R-T) leads.
9Start the engine, then measure the voltage. (Tester
range: AC300V)
GOODTOO LOW
DOES NOT GENERATE
AC coil 1
W
Or
WW
W
W Br
G
BrBr
Br
Br R
S
T
R
S
T AC coil 2
AC coil 1 AC voltage:
130 ~ 260 V at 20 °C (68 °F)
Magnetic force is weak.
Replace the magneto rotor.
AC coil 1 resistance inspection
9Stop the engine.
9Measure the resistance between Brown-Green 
(R-S), Green-Brown (S-T), and Brown-Brown (R-T) 
leads. (Tester range: Ω×1)
SPECIFICATION OUT OF SPECIFICATION
W
Or
WBr
G
Br AC coil 1R
S
T
R
S
T AC coil 2
AC coil 1 resistance:
0.47 
Ω± 20% at 20 °C (68 °F)
Replace the AC coil 1.
*
7VV10-05  02.10.7 1:55 PM  Page 8 
						

							5-9
GENERATOR SYSTEMELEC
AC coil 2 AC voltage inspection
9Connect White-Orange (R-S), Orange-White (S-T), 
and White-White (R-T) leads.
9Start the engine, then measure the voltage. (Tester
range: AC120V)
GOODTOO LOW
DOES NOT GENERATE
AC coil 2W
Or
WW
W
W Br
G
BrBr
Br
Br AC coil 1R
S
T
R
S
T
AC coil 2 AC voltage:
13.5 ~ 23.0 V at 20 °C (68 °F)
*
Magnetic force is weak.
Replace the magneto rotor.
AC coil 2 resistance inspection
9Stop the engine.
9Measure the resistance between White-Orange 
(R-S), Orange-White (S-T), and White-White (R-T) 
leads. (Tester range: Ω×1)
SPECIFICATION OUT OF SPECIFICATION
AC coil 2W
Or
WBr
G
Br R
S
T
R
S
T
AC coil 1
AC coil 2 resistance:
0.17 
Ω± 20% at 20 °C (68 °F)
Replace the AC coil 2.
Replace the control unit.
Economy switch continuity inspection
9Switch “ON” →Continuity
9Switch “OFF” →No Continuity
CONTINUITY NO CONTINUITY
7VV10-05  02.10.8 8:11 PM  Page 9 
						

							5-10
GENERATOR SYSTEMELEC
TROUBLESHOOTING CHART
WEAK OR NO DC CURRENT
Rated engine speed inspection.
9Operate the engine with no load.
9Set the economy switch to “OFF”.
5,000 r/min
GOOD OUT OF SPECIFICATION
Check the throttle control system.
Refer to “THROTTLE CONTROL SYSTEM” in
CHAPTER 6.
Check the DC circuit breaker.
GOOD DISCONNECTED
Replace the DC circuit breaker.
DC coil DC voltage inspection
9Connect Blue leads.
9Start the engine, then measure the voltage. (Tester
range: DC 20V)
GOODTOO LOW
DOES NOT GENERATE
L
LL
L
DC coil DC voltage:
13.5 ~ 23.0 V at 20 °C (68 °F)
Replace the rectifier.
DC coil resistance inspection
9Stop the engine.
9Measure the resistance between Blue leads. 
(Tester range: Ω×1)
SPECIFICATION OUT OF SPECIFICATION
L
L
DC coil resistance:
0.07 Ω± 20% at 20 °C (68 °F)
Replace the DC coil.
Magnetic force is weak.
Replace the magneto rotor.
7VV10-05  02.10.7 1:41 PM  Page 10 
						

							6-1
ENGINETRBL
TROUBLE SHOOTING
ENGINE
ENGINE DOES NOT START
Check that the oil warn-
ing light turns ON by
pulling the starter rope.
LIGHT ON
DOSE NOT
TURN ON
Check engine oil level.
SUFFI-INSUFFI-
CIENTCIENT
Check fuel level.
SUFFI-INSUFFI-
CIENTCIENT
Check fuel cock lever
position.
“ON” “OFF”
Check if fuel flows to fuel
cock.
GOOD
NO GOOD
Check connections between oil warning unit
and oil level switch.
GOOD NO GOOD
Check if fuel is deteriorated.
GOOD NO GOOD
Replace oil
warning
light, oil
warning
unit, or oil
level
switch.
Add.
Add.
Replace.
Set to
“ON”.
Clean or
replace
fuel pump.
Clean or
replace
fuel cock
Replace
the fuel
TCI unit.
Clean or
replace.
Remove spark plug,
attach it to spark plug
cap, and then ground the
spark plug to check for
spark.
GOOD
WEAK OR
SPARKNO SPARK
Check if fuel is deteriorated.
GOOD NO GOOD
9Check spark plug for dirt and check spark
plug gap.
9Check for voltage leakage due to faulty con-
nection or broken insulation of the high ten-
sion cord.
9Check TCI unit connector for corrosion or
faulty connection.
9Check the ignition system. Refer to “IGNI-
TION SYSTEM” in CHAPTER 5.
GOOD NO GOOD
*
Install a substitute TCI unit to check spark con-
ditions.
GOOD NO GOOD
7VV10-06  02.10.4 10:41 AM  Page 1 
						

							6-2
ENGINETRBL
Check carburetor for
clogged passages or fuel
overflow.
GOOD
NOT GOOD
*
Replace.
Measure valve clear-
ance.
GOOD
OUT OF
SPECIFICATIONAdjust.
Check compression
using compression
gauge.
OUT OFGOODSPECIFICATION
Check valve face and
valve seat for wear.
GOOD
WEARResurface
or replace.
Check if the marks on
the crankshaft and
camshaft are aligned.
GOOD
NO GOODCorrect or
replace.
Check if there is seizure
or wear on the piston,
piston ring, or cylinder.
GOOD
SEIZURE
OR WEARRebore or
replace.
Check the condition of the throttle control sys-
tem. Refer to “THROTTLE CONTROL SYS-
TEM”.
1
2
3
4
5
6
7
7VV10-06  02.10.4 10:41 AM  Page 2 
						

							6-3
ENGINETRBL
ENGINE STARTS BUT STALLS
Check fuel level.
SUFFI-INSUFFI-
CIENTCIENTAdd.
Clean.
Check if fuel cock is
clogged.
GOOD
NO GOOD
Clean.
Check if fuel hose is
clogged.
GOOD
NO GOOD
9Check if carburetor
retaining nuts are
loose.
9Check if there is air
suction due to a dam-
aged carburetor joint or
gasket.
GOOD
NO GOOD
9Tighten the
carburetor
bolts 
securely.
9Replace
carburetor
joint or gas-
ket with a
new one.
Measure valve clear-
ance.
GOOD
OUT OF
SPECIFICATIONAdjust.
Check compression
using compression
gauge.
GOOD
OUT OF
SPECIFICATIONCheck piston, piston ring and cylinder.
GOOD NO GOOD
Replace.
Check air gap.
GOOD
NO GOODReplace.
Check the condition of the throttle control sys-
tem. Refer to “THROTTLE CONTROL SYS-
TEM”.
7VV10-06  02.10.4 10:41 AM  Page 3 
						

							6-4
ENGINETRBL
ENGINE SPEED DOES NOT INCREASE
Check if the electric equipment consumes too much
wattage for this generator.
GOOD TOO MUCH
Use a generator with a larger capacity.
Check air filter element for dirt.
GOOD NO GOOD
Clean.
Check spark plug for dirt and check spark plug gap.
GOOD NO GOOD
Clean or adjust.
Check valve clearance.
GOOD NO GOOD
Adjust.
Check if main passages such as, the main jet, in the
carburetor are clogged.
GOOD NO GOOD
Disassemble or clean.
Check for air suction due to a damaged throttle shaft
seal, carburetor joint, or gasket.
GOOD NO GOOD
Disassemble or replace.
Check compression using compression gauge.
GOODTOO HIGH
TOO LOWDecarbonize combustion chamber if
there are carbon deposits.
Check valve face and valve seat for wear.
GOOD NO GOOD
Resurface or replace.
Check if the marks on the crankshaft and camshaft
are aligned.
GOOD NO GOOD
Correct.
Check if there is seizure or wear on piston, piston ring,
or cylinder.
GOODSEIZURE OR
WEAR
Rebore or replace.
Check the condition of the throttle control system.
Refer to “THROTTLE CONTROL SYSTEM”.
7VV10-06  02.10.4 10:41 AM  Page 4 
						

							6-5
ENGINETRBL
ENGINE SPEED IS UNEVEN
Check fuel level.
SUFFICIENT INSUFFICIENT
Add.
Check if fuel is deteriorated.
GOOD NO GOOD
Replace fuel.
Check if fuel tank cap is clogged.
GOOD NO GOOD
Replace.
Check if fuel cock is clogged.
GOOD NO GOOD
Clean.
Check fuel pump operation.
GOOD NO GOOD
Replace.
Check spark plug for dirt and check spark plug gap.
GOOD NO GOOD
Clean, adjust or replace.
While the engine is operating, pull the choke knob
approximately 1/3 to 1/2 way out, and then check the
engine operating condition.
STABLE UNSTABLE
Resurface or replace.
Check for air suction due to a damaged throttle shaft
seal, carburetor joint, or gasket.
GOOD NO GOOD
Disassemble or replace.
Check if slow or main passages such as, the pilot jet
and main jet, in carburetor are clogged.
GOOD NO GOOD
Disassemble or clean.
Check valve face and valve seat for wear.
GOOD NO GOOD
Resurface or replace.
Check if there is seizure or wear on piston, piston ring,
or cylinder.
GOODSEIZURE OR
WEAR
Rebore or replace.
Check the condition of the throttle control system.
Refer to “THROTTLE CONTROL SYSTEM”.
Check valve clearance.
GOOD
OUT OF SPECIFICATIONAdjust.
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							6-6
THROTTLE CONTROL SYSTEMTRBL
THROTTLE CONTROL SYSTEM
ENGINE DOES NOT START, ENGINE STARTS BUT STALLS, ENGINE SPEED
DOES NOT INCREASE, OR ENGINE SPEED IS UNEVEN.
Check AC  output.
GOOD NO GOODRefer to “GENERATOR SYSTEM” in
CHAPTER 5.
Rotate the shaft of the throttle control motor to check
if it turns smoothly with slight resistance.
GOOD NO GOOD
Replace the throttle control motor.
Replace the throttle control motor.
Replace the control motor.
Measure the coil resistance between 3-1, 3-2, 3-4,
and 3-5 of the throttle control motor.
(Tester range: Ω×1)
SPECIFICATION OUT OF SPECIFICATION
Coil resistance:
250 Ω± 20% at 20 °C (68 °F)
Check the connections of the wire harness connectors
and couplers, and the wires for an open circuit or short
circuit.
GOOD NO GOOD
Correct or replace.
7VV10-06  02.10.4 10:41 AM  Page 6