Guardian 4389 Repair Manual page 105

DC CONTROL
Figure 12. Clamp-On Ammeter
TACHOMETER:
A tachometer is available from your Generac Power
Systems source of supply. Order as P/N 042223. The
tachometer measures from 800 to 50,000 RPM,
Figure 13.
Figure 13. Tachometer
TEST BRACKET:
A starter motor test bracket may be made as shown
in Figure 14. A growler or armature tester is available
from an automobile diagnostic service supplier.
2.625"
0.5"
12"
DRILL TWO HOLES — 1/2"
FOR STARTER
MOUNTING BRACKET
Figure 14. Test Bracket
PART 4
METAL STOCK
1/4" THICK STEEL
3.5"
1.0"
4"
2"
DRILL TWO HOLES — 1/2"
FOR MOUNTING TACHOMETER
TAP FOR 1/4-20 NC SCREWS
REMOVE STARTER MOTOR:
It is recommended that the starter motor be removed
from the engine when testing starter motor perfor-
mance. Assemble starter to test bracket and clamp
test bracket in vise, Figure 15.
TESTING STARTER MOTOR:
1. A fully charged 12 volt battery is required.
2. Connect jumper cables and clamp-on ammeter as
shown in Figure 15.
3. With the starter motor activated (jump the terminal on the
starter contactor to battery voltage), note the reading on
the clamp-on ammeter and on the tachometer (rpm).
Note: Take the reading after the ammeter and
tachometer are stabilized, approximately 2-4
seconds.
4. A starter motor in good condition will be within the fol-
lowing specifications:
Single Cylinder
Minimum rpm
Maximum Amps
STARTER
CONTACTOR
STARTER
MOTOR
TACHOMETER
VISE
Figure 15. Testing Starter Motor Performance
SECTION 4.4
DIAGNOSTIC TESTS
V-twin
800 4500
9 50
CLAMP ON
AMP METER
12 VOLT
BATTERY
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