Starting in 1974, a vacuum operated automatic choke replaces the manual choke previously used. The automatic choke uses a choke cap which contains a heating element, to speed up choke valve opening, and thus reduce CO emissions during warm-up.
The heating element gets its power from a special tap on the voltage regulator, when the ignition is on and the engine running.
REMOVAL & INSTALLATION
- Remove the air cleaner assembly from the carburetor.
- Remove the electrical lead which runs from the choke cap to the voltage regulator.
- Disconnect the setting piston from the auxiliary choke diaphragm.
- Remove the 3 screws which secure the choke cap to the carburetor and remove the cap.
- Be sure that the choke lever is positioned in the middle of the bi-metal before installing the cap.
After installation, check to see that the carburetor choke valve closes when the cap is turned counterclockwise. Align the setting marks on the choke housing and cap. See the Carburetor Section for further choke adjustments.
- Disconnect the choke lead from the voltage regulator.
- Connect an ohmmeter between the lead that you just disconnected and a good ground. The ohmmeter should read about 9 ohms.
- Replace the choke cap if the reading shows an opened (no resistance) or shorted (infinite resistance) heating coil.
- If the choke coil is working properly, but a fault is suspected in the choke heater system, substitute a new voltage regulator to see if it will solve the problem.