Generac Power Systems 941-2, 940-2 Section AUTOMATIC CHOKE, Operational Check And Adjustment

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 regular timed cycles. Each time the choke solenoid is ener- gized, it closes the carburetor choke valve. The circuit board's choke timer circuit energizes the choke sole- noid (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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