Section 3.5

AUTOMATIC CHOKE

GENERAL
The GV-220 vertical shaft engines are equipped with
an automatic choke. A choke solenoid is attached to
the carburetor choke shaft by means of a choke con-
trol link. Solenoid operation is controlled by the A6060
circuit board. The circuit board energizes and de-
energizes the solenoid cyclically at a rate dependent
on ambient temperature during engine cranking only.
DESCRIPTION
See Figure 1. The CHOKE SOLENOID is retained to
a CHOKE COVER by two No. 4-40 SCREWS, LOCK-
WASHERS and FLATWASHERS. The two screw
holes in the COVER are slotted to provide for axial
adjustment of the CHOKE SOLENOID. A COTTER
PIN retains a CHOKE LINK to the SOLENOID. A
CHOKE BI-METAL & HEATER is retained to the
SOLENOID by two No. 4-40 SCREWS, LOCKWASH-
ERS and FLATWASHERS.

Figure 1. Choke Solenoid Parts

OPERATION

NOTE: Also see Part 6, "ENGINE ELECTRICAL

SYSTEM". The section on DC control system

includes additional information on choke opera-

tion and the A6060 circuit board.

When the engine is being cranked, A6060 circuit
board action energizes the choke solenoid in regu-
lar timed cycles. Each time the choke solenoid is
energized, it closes the carburetor choke valve. The
circuit board's choke timer circuit provides ener-
gizes the choke solenoid (pulls it in) about every 2
to 5 seconds'
When the engine starts, cranking is terminated. The
choke action is then terminated and the choke setting
is determined by a choke heater (CH).
OPERATIONAL CHECK AND ADJUSTMENT
OPERATIONAL CHECK:
Crank the engine. During cranking, the choke sole-
noid should pull in about every 2 to 5 seconds. If it
does NOT pull in, try adjusting the choke.
PRE-CHOKE ADJUSTMENT:
With the solenoid NOT pulled in, the carburetor choke
valve (choke plate) should be about 1/8 inch from its
full open position. If necessary, use needle nose pli-
ers to bend the tip of the BI-METAL until a 1/8 inch
setting is obtained.
CHOKE SOLENOID ADJUSTMENT:
Loosen the two screws that retain the choke solenoid
to its cover. Adjust axial movement of the solenoid
plunger by sliding the solenoid in the slotted screw
holes of the cover.
Adjust plunger axial movement until (with the carbure-
tor choke valve closed) the plunger is bottomed in the
solenoid coil. That is, until the plunger is at its full
actuated position.
With the choke valve (choke plate) closed and the
plunger bottomed in its coil, tighten the two screws.

Figure 2. Choke Adjustment

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