Yamaha EF1000iS Service Manual page 85

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