20601 Old State Road, Haubstadt, Indiana 47639
Production of Economy engines began in Sparta, Michigan, by
mid-1909. For the year prior to that, Economy engines were provided
for Sears, Roebuck & Co. mail order by the Waterloo Gas Engines
Company. At Sparta the model A was the first one produced. It would
appear that the engine designer took several ideas from the
Waterloo engine. The Sparta Economy had some unique features. One
was the fuel system that was similar to that used on the Waterloo
Economy. The fuel valve was more like a gate valve than a needle
valve used on most systems. The fuel was metered by a small hole in
the side of a 1/8 inch pipe that extended
into the main air intake flow. The valve served more as on and off
rather than an adjustment. A small pet-cock is positioned to allow
a small amount of fuel into a cap that serves as an adjustable
choke on the bottom of the air intake tube.
Another unique feature is the side rod latch on the 4 HP and
larger sizes. The side rod can be latched so the exhaust valve is
held open while cranking. Once the flywheels are spinning fast
enough, the latch is released and, hopefully, the engine will
start.
The fuel tank is unique in that it’s cast into the base and
requires no separate sheet metal tank common to most engines. The
fuel fill spout is handy–it is funnel shaped at the top. That is
fine until it rains and then water is funneled in around the plug
cap and into the fuel tank if the cap isn’t tight. If it is
tight, then the question is, ‘How do you take out the plug
without the water around it in the funnel running into the
tank?’
Another unique feature is the comparatively complex
governor/speed control mechanism. It was invented by Peter Holm and
used on the Sparta Economy models A, B and C while the patent was
pending. Sears saw fit to drop the use of this mechanism even
before the actual patent was granted, and the mechanism disappeared
from the market. For the next few years Sparta Economy engines had
no speed adjustment other than tinkering with the governor
springs.
Shown here is an example of a 4 HP Sparta Economy model A. It
has a 4? inch bore and 9 inch stroke. The compression appears to be
higher than on other engines of that era and later. That makes it
difficult to turn over by hand. That is likely why the side rod
latch is provided. The very design of the cam makes it impossible
to retard the ignition when starting, further complicating the
starting process.
Approximately 1200 of the Sparta Economy model A engines were
produced, making these unusual engines somewhat scarce and hard to
find. Luckily, an original color sales brochure still exists along
with an original operators manual and parts book. The instruction
book has more detail about the function of the various engine parts
than any other that I’ve seen.