Lincoln Electric RANGER 250 SVM150-A Service Manual page 71

F-21
ENGINE THROTTLE ADJUSTMENT TEST (continued)
FIGURE F.5 – HIGH IDLE ADJUSTMENT
THROTTLE LINKAGE
Frequency Counter Method
1. Plug the frequency counter into one of the
120 VAC auxiliary receptacles.
2. Start the engine and check the frequency
counter. At HIGH IDLE (3700 RPM), the
counter should read between 61 and 63
Hz. At LOW IDLE (2400 RPM), the counter
should read between 39 and 40 Hz. Note
that these are median measurements;
hertz readings may vary slightly above or
below.
3. If either of the readings is incorrect, adjust
the throttle as follows:
TROUBLESHOOTING & REPAIR
3/8" HIGH IDLE
ADJUSTMENT NUT
CHOKE CABLE
RANGER 250
FIGURE F.6 – LOW IDLE ADJUSTMENT
7/16" LOW IDLE
ADJUSTMENT NUT
SOLENOID
HOUSING
Adjust HIGH IDLE: Use the 3/8" wrench to
loosen the spring-loaded adjustment nut. See
Figure F.5 for location of the adjustment nut.
Turn the nut clockwise to increase the HIGH
IDLE speed. Adjust the speed until the fre-
quency reads between 61 and 63 Hz.
Adjust LOW IDLE: First make sure there is no
load on the machine. Set the IDLER switch to
AUTO and wait for the engine to change to low
idle speed. Use the 7/16" wrench to adjust the
solenoid nut, which changes the amount of
throw in the throttle lever arm. See Figure F.6
for the location of the adjustment nut. Adjust
the nut until the frequency reads between 39
and 40 Hz.
F-21
MUFFLER
ROD