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SECTION 6A
FUEL SYSTEMS AND GOVERNORS
If the plunger is drawn into the solenoid, the shut-
down control is functioning properly.
If the plunger is not drawn into the solenoid, the
solenoid is faulty and must be replaced.
As a temporary fix, until a replacement solenoid can
be obtained, the plunger can be removed from the
shutdown control and the solenoid reinstalled minus
the plunger.*
After replacing solenoid, refer to Section 6A for carbu-
retor adjustment.
*The removal of the plunger will not affect normal car-
buretor function; however, to prevent unfiltered air from
entering the carburetor, the defective solenaid must be
reinstalled over shutdown control vent hole, after the
plunger has been removed.
ENGINES EQUIPPED FOR DUAL FUEL
Hard starting and low power on units equipped for
dual fuel (gasoline/LPG) have been traced to two
causes:
1. Improper size venturi
2. Improper adjustments to regulator and adapter.
The following changes and/or adjustments must be
made to the unit to assure proper
performance.
NOTE: When switching from gasoline to LPG make
sure that gasoline supply has been tuned off
and that all gasoline is vacated from the float
bow! and fuel lines by running the engine out
of gasoline.
1. Check venturi size of adapter.
a. If adapter is equipped with no. 26 size venturi,
move on to adjustment procedure.
b. If the adapter is equipped with a no. 20 size
venturi, (see Figure 6A-24) remove no. 20
venturi and replace with no. 26 size venturi.
64.18
УА — —Load Screw
Adaptor
Venturi
Venturi
Size
(Last 2
digits)
Reference #
only
Figure 6A-24. Venturi Identification.
2. Check and make adjustments to regulator and
adapter.
a. Before starting engine, set the mixture load
screw at the adapter 1-1/2 tums out from
closed.
b. If engine is equipped with Century brand regu-
lator/vaporizer, no idle adjustment is neces-
sary. Move to Step C. If equipped with Beam
model 50 or 50Е secondary regulator, proceed
as follows:
Start engine, with engine running, manually
hold throttle against idle stop screw. Confirm
that engine is running at or below 1500 RPM
with tachometer.
Tum the idle mixture screw located on sec-
ondary regulator IN toward the rich side until
RPM drops.
(This should be confirmed with a
tachometer.)
Then turn screw OUT toward the
lean side until engine RPM recovers and
again, begins to fall off. At this point, again
turn the screw IN just until the engine reaches
top RPM and stop.
NOTE:
Setting the idle mixture screw halfway be-
tween the two ranges will cause a rich
mixture setting.
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