Guardian 4389 Repair Manual page 113

DC CONTROL
Figure 28. Testing the Oil Temperature Switch
RESULTS:
1. If the switch fails Step 4, or Steps 8-9, replace the
switch.
2. If INFINITY was NOT measured in Step 5, repair or
replace Wire 85 between the Circuit Board and the High
Oil Temperature Switch.
TEST 62 - CHECK AND ADJUST VALVES
DISCUSSION:
Improperly adjusted valves can cause various engine
related problems including, but not limited to, hard
starting, rough running and lack of power. The valve
adjustment procedure for both the single cylinder and
the V-twin engines is the same.
PROCEDURE (INTAKE AND EXHAUST):
Make sure that the piston is at Top Dead Center
(TDC) of it's compression stroke (both valves closed).
The valve clearance should be 0.05-0.1mm (0.002-
0.004 in) cold.
Check and adjust the valve to rocker arm clearance
as follows:
1. Remove the four (4) screws from the rocker cover.
2. Remove the rocker cover and rocker cover gasket.
3. Loosen the rocker arm jam nut. Use a 10mm allen
wrench to turn the pivot ball stud and check the clear-
ance between the rocker arm and the valve stem with a
flat feeler gauge (see Figure 29).
4. When the valve clearance is correct, hold the pivot ball
stud with the allen wrench and tighten the rocker arm
jam nut. Torque the jam nut to 174 inch pounds. After
tightening the jam nut, recheck the valve clearance to
make sure it did not change.
PART 4
Figure 29
5. Re-install the rocker cover gasket, rocker cover and the
four (4) screws.
RESULTS:
Adjust valve clearance as necessary, the retest.
TEST 63 - CHECK FUEL REGULATOR
DISCUSSION:
The fuel regulator is rarely the cause of a hard start or
no start condition. The most common causes are insuf-
ficient fuel pressure supplied to the unit, or the adjust-
ment screws on the fuel regulator being out of adjust-
ment. The fuel regulator is an "ON DEMAND" type.
During cranking and running, negative pressure from
the airbox or carburetor unseats the fuel regulator
diaphragms and allows fuel flow through the regulator.
PROCEDURE:
Note: Step 1 of this procedure pertains to V-twin
engines without set pins only.
1. If the adjustment screw settings are in question, reset as
follows:
a. Turn adjustment screws clockwise all the way
in, then turn out counterclockwise two and one
half full turns. This will provide a starting point
for further adjustment.
2. Turn off utility power to the main distribution panel in the
house. This can be done by switching the service main
breaker to the OFF or "Open" position.
3. Allow the generator to start. Before loading the genera-
tor, confirm that the No Load Frequency, with the roof
open and the door off, is set to 63-63.5 Hz. Transfer
load to emergency circuits.
4. Turn on appliances. lights, pumps, etc., that are on the
emergency circuits in an attempt to fully load the gener-
ator. Be cautious not to overload the generator. Use the
following chart as a guide:
SECTION 4.4
DIAGNOSTIC TESTS
Page 111