Generac Power Systems 10 kW LP Repair Manual page 141

DC CONTROL
PROCEDURE, ADJUSTING MAGNETO FLYWHEEL GAP:
note: the air gap between the ignition magneto
and the flywheel on single cylinder engines is not
adjustable. proceed directly to Step 10 for single
cylinder engines. For V-twin engines, proceed as
follows.
1. See Figure 34. Rotate the flywheel until the magnet is
under the module (armature) laminations.
2. Place a 0.008-0.012 inch (0.20-0.30mm) thickness
gauge between the flywheel magnet and the module
laminations.
note: a business card is approximately 0.010
inch thick.
3. Loosen the mounting screws and let the magnet pull the
magneto down against the thickness gauge.
4. Tighten both mounting screws.
5. To remove the thickness gauge, rotate the flywheel.
6. Repeat the above procedure for the second magneto.
0.008-0.012" GAUGE
MAGNETO
Figure 34. Setting Ignition Magneto (Armature)
Air Gap
7. Repeat Test 70 and check for spark across the spark
tester gap
a. A spark test may be conducted with unit dis-
sembled by following this procedure.
b. Battery must be connected.
c. J2 Connector must be connected to the printed
circuit board.
d. Remove Wire 56 from the SCR located beneath
the printed circuit board.
Warning: make sure all debris is cleared from the
engine compartment and all body parts are clear
from flywheel before proceeding.
e. Refer to Test 70 to check for spark.
f. Utilizing a jumper wire, connect a wire to the
15B terminal block. Connect the other end to
Part 4
where Wire 56 was disconnected in Step 7. The
engine should crank once the jumper from 15B
is connected.
8. If spark was not indicated, replace magnetos.
note: if gap is only adjusted, ensure to properly
test the magnetos by cranking the engine over
before reassembly occurs. Spark should be
present on both cylinders before reassembly
should be completed.
9. If air gap was not out of adjustment, test ground wires.
10. Set a VOM to the measure resistance.
11. Disconnect the engine wire harness from the ignition
magnetos (Figure 35).
a. On V-twin generators, remove Wire 18 from the
stud located above the oil cooler. See Figure 45.
b. On single cylinder generators, disconnect Wire
18 at the bullet connector. See Figure 44.
ENGINE
WIRE
HARNESS
SPARk PLUG
SPARk PLUG
Figure 35. Engine Ground Harness
12. Connect one meter test lead to one of the wires removed
from the ignition magneto(s). Connect the other test
lead to frame ground. INFINITY should be measured. If
CONTINUITY is measured, replace the shutdown harness.
13. Now check the flywheel magnet by holding a screwdriver
at the extreme end of its handle and with its point down.
When the tip of the screwdriver is moved to within 3/4
inch (19mm) of the magnet, the blade should be pulled
in against the magnet.
14. For rough running or hard starting engines check the fly-
wheel key. The flywheel's taper is locked on the crankshaft
taper by the torque of the flywheel nut. A keyway is provided
for alignment only and theoretically carries no load.
note: if the flywheel key becomes sheared
or even partially sheared, ignition timing can
change. incorrect timing can result in hard start-
ing or failure to start.
15. As stated earlier, the armature air gap is fixed for single
cylinder engine models and is not adjustable. Visually
inspect the armature air gap and hold down bolts.
sEctioN 4.4
DiaGNostic tEsts
STUD CONNECTOR
WIRE 18 TO
CIRCUIT BOARD
REMOVE LEADS
Page 139