Kohler 6VSG Service Manual page 62

Problem Possible Cause
Lacks Air intake
power restriction,
inadequate cooling
Generator
overloaded
Spark plug(s)
Spark plug
connections
Low fuel pressure
Fuel line restriction
Fuel regulator
Engine not running
at rated rpm
Engine power loss
Governor
malfunction or
misadjustment
Ignition system
Low output Generator
or overloaded
excessive
Incorrect controller
drop in
settings
voltage
Incorrect controller
voltage settings
Alternator
Controller
Stator
Rectifier
Low engine speed
causing voltage
roll-off
W/D = Wiring Diagram(s) (Section 7)
I/M = Generator Set Installation Manual
S/S = Generator Set Specification Sheet
62 Section 4 Troubleshooting
Test
Inspect air intakes and exhaust for
obstructions.
Check air cleaner.
Reduce electrical load and check
operation.
Check spark plugs.
Check tightness and condition of
spark plug wires.
Check fuel pressure at carburetor
outlet. Check for adequate fuel
pipe size and meter capacity for
generator set and all gas-fired
appliances.
Check fuel pipe size.
Check function of fuel regulator.
Check controller setting for engine
model. *
Check engine speed.
Refer to the engine service
manual for troubleshooting and
repair instructions.
Test governor.
See the engine service manual for
service procedures.
Reduce electrical load and check
operation.
Check the controller settings. *
Check the controller voltage
settings. *
Perform alternator
troubleshooting, Section 5.2.
Check the controller settings.
Test the controller as described in
Section 4.10.
Test stator for open, grounded, or
shorted windings.
Perform Rectifier Troubleshooting,
Section 5.3.
Check system voltage, system
frequency, and engine model
settings.
Check engine speed setting.
Engine problem.
Engine S/M = Engine Service Manual
O/M = Generator Set Operation Manual
Corrective Action
Clear air intakes and exhaust
area. Maintain clearances shown
on the genset dimension drawing.
Replace air cleaner element.
Unplug some lights or appliances
connected to the generator set.
Regap or replace plug(s).
Tighten or replace spark plug
wires.
Contact fuel supplier to replace
pipe and/or meter as required to
provide sufficient fuel supply
pressure for the generator set and
all gas-fired appliances.
Contact fuel supplier to provide
larger pipe.
Repair or replace fuel regulator.
Select the correct engine model. *
Adjust engine speed.
Refer to the engine service
manual for troubleshooting and
repair instructions.
Adjust governor.
See the engine service manual for
service procedures.
Unplug some lights or appliances
connected to the generator set.
Adjust the controller settings. *
Adjust the controller voltage
settings. *
Make repairs based on results
from alternator troubleshooting,
Section 5.2
Adjust controller settings.
See Section 4.10.
Replace stator if faulty windings
are found.
Make repairs based on Rectifier
Troubleshooting, Section 5.3
Change the controller settings if
not correct. *
Adjust engine speed setting.
Troubleshoot the engine.
Reference
I/M
O/M
—
O/M
Engine S/M
Section 5.8
Section 5.8
Section 5.8.2
Section 3.3
Engine S/M
Section 5.6
Engine S/M
—
Section 3.3
Section 3.3
Section 5.2
Section 3.3
Section 4.10
Section 5.3
Section 5.3
Section 3.3
Section 3.3
Engine S/M
TP-6844 1/13