Design Improvements for the Zenith 601 HDS: Primer
The cable-operated choke system was not appealing, so instead
a standard primer was installed.
The primer pump is located on the instrument panel on the left hand side
between the ignition switches and the fuel transfer pump switches.
The primer injects the fuel into the two
ports of the pressure equalizing tube that connects the two intake
manifolds. Without fail, two squirts result in an instant start
of the engine.