Troubleshooting & repair, Engine throttle adjustment test (continued) – Lincoln Electric POWER-ARC 4000 SVM103-A User Manual
Page 57
TROUBLESHOOTING & REPAIR
POWER-ARC 4000
F-16
ENGINE THROTTLE ADJUSTMENT TEST (continued)
FIGURE F.4 - BLOWER PADDLE MARKED FOR STROBE-TACH METHOD
MARK
TEST PROCEDURE
This test can be conducted by any of three
methods.
Strobe-tach Method:
1. Stop the engine and remove the spark plug
wire to prevent accidental kickback or
starting.
2. With the black or red marking pencil, place
a mark on one of the blower paddles,
which can be reached through the vent
slots in the end bracket. See Figure F.4.
3. Connect the strobe-tach according the
manufacturer’s instructions.
4. Reconnect the spark plug wire and start
the engine. Direct the strobe-tach light on
the blower paddle and synchronize it to the
rotating mark. The tach should read 3700
RPM.
5. Use the 7/16 wrench to turn in the spring-
loaded adjustment nut. Increase the high
idle speed until the tach reads 3700 RPM.
See Figure F.5 for location of the adjust-
ment nut.
Frequency Counter Method:
1. Plug the frequency counter into one of the
115 VAC auxiliary receptacles.
2. Start the engine and check the frequency
counter. At the proper RPM (3700), the
counter should read 61.7 Hz.
3. Use the 7/16 wrench to turn in the spring-
loaded adjustment nut. Increase the high
idle speed until the frequency counter
reads 61.7 Hz. See Figure F.5 for location
of the adjustment nut.
Oscilloscope Method:
1. Connect the oscilloscope according to the
manufacturer’s instructions. At 3700 RPM,
the waveform should exhibit a period of
16.2 milliseconds. Refer to the NORMAL
OPEN CIRCUIT VOLTAGE WAVEFORM
(115 VAC SUPPLY) HIGH IDLE - NO LOAD
in this section of the manual.
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