Test 62 - Check And Adjust Valves; Test 63 - Check Fuel Regulator; (7 Kw Natural Gas Units Only) - Guardian 5240 Diagnostic Repair Manual

DC CONTROL
Figure 34. 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 35).
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
JAM NUT
Figure 35
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

(7 KW NATURAL GAS UNITS ONLY)

DISCUSSION:
The fuel regulator is rarely the cause of a hard start
or no start condition. The most common causes are
insufficient fuel pressure supplied to the unit, or the
adjustment screw on the 7 kW fuel regulator being out
of adjustment. 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: No adjustments are available on V-twin
engines units.
1. 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.
2. 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 62-63 Hertz. Transfer
load to emergency circuits.
3. Turn on appliances, lights, pumps, etc., that are on the
emergency circuits in an attempt to fully load the gen-
erator. Be cautious not to overload the generator. Use
the following chart as a guide:
Unit 120 Volts
7 kW 50.0 amps
SECTION 4.4
DIAGNOSTIC TESTS
BALL STUD
0.076 mm
(0.003") SHIM
240 Volts
25.0 amps
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