Model K Mixer
The 3-12hp model K engines used a mixer
somewhat like that of the earlier N Kerosene but of a new design.
It still contained a gasoline reservoir for starting purposes and
still had dual needle valves but they were now arranged differently.
The reservoir's suction pipe contained its own check valve which is
accessed by a pipe plug. An auxiliary air valve was now
included as well. This valve utilized a light spring to hold
it closed. It's purpose was to admit additional air during
heavy loads to prevent the fuel mixture from becoming too rich.
It will have 3 small holes drilled around the center stem and these
should be kept clear. The valve itself should be lubed with a
light oil and kept working freely at all times. All sizes of
early engines initially had the water injection feed located in the
mixer body itself. This was quickly changed to feed into the
throttle elbow itself on the 3 and 5hp engines. The larger
sizes retained the same feed location but the casting now
incorporated a tee with plug to drain the system in cold weather.
An elliptical cast brass butterfly valve was set into the throttle
elbow and secured to the bell crank with a taper pin. Most
engines had a notch milled into the valve to achieve a minimum
amount of air flow. Starting in 1918 a setscrew was installed
into the elbow, it lined up with this notch when the butterfly valve
was in its closed position. The screw apparently was used to
close up the notch if required. The mixer also served as an
overflow chamber if the engine was fitted with a fuel pump and
outdoor main fuel tank. A series of welch plugs were located
around the mixer body. They were initially there due to the
core work required on the casting but also served a dual purpose.
Fuel was pumped into one of the welch plugs located in the casting's
side. A standpipe was located in place of the bottom welch
plug, it serving as an overflow to keep the fuel level constant.
The "gasoline" throttle once used for staring only was now the main
fuel supply throttle valve. Now what was the main fuel tank in
the base became the starting tank and the "kerosene" throttle was
used for starting.
