3801 Purdue Drive, Bakersfield, California 93306
Gentlemen, I would like to tell you about my 4 HP Cushman (light
weight) also referred to as a binder engine. This engine was kept
light by using only one flywheel, and on the opposite side is a
clutch pulley for a 4′ flat belt.
This engine was designed to be run with a model T coil and had a
point set-up on the cam shaft. This set-up was a complete disaster
for me, so I used a Fairbanks Morse model FM J impulse type magneto
driven by a chain sprocket on the cam shaft. This worked okay,
except you cannot get a fine timing adjustment with chain links.
So, I bored out the chain sprocket and fit it over a hub on the cam
shaft and used set screws for fine tuning. Some later models have a
Dixie magneto driven with right angle gears with special brackets
holding the magneto. (As shown in picture from the instruction
manual.)
The original cooling tanks were round and fit into a round part
in the frame that was referred to as the banjo frame. Because my
engine is already doctored up, it was easier for me to make the
tank as you see it. The Schebler carburetor, which was all brass,
was an education by itself. It is hard to adjust because it is a
large carburetor used on a small engine. I designed a Ventura tube
for it and solved all my problems. There is an exhaust pre-heating
system design on the intake manifold that makes the engine very
efficient on fuel.
This engine has a very unusual lubrication system. Because of
the closed crankcase, it has a dip type splash to the crank thro
and also two tubes that pick up oil to the main bearings. This
caused the bearings to leak oil, so I removed the tubes and put in
grease cups to pack the bearings. Now the engine runs clean.
There is a drip oiler on the side of the cylinder, which is
rather unusual for a closed crankcase engine, but the instruction
book says this drip oiler, besides oiling the piston, helps to keep
the oil level up while running. Another good feature on this engine
is a built-in gear driven water circulating pump. It is well
designed and well built.
# 1 picture shows the clutch pulley belted to a small air
compressor that puts pressure in the small air tank and on it is a
very old exhaust whistle seen on pictures # 2, #3, and #4. Picture
#5 shows the Fairbanks magneto that is chain driven from the cam
shaft. #6 shows the magneto, gear driven water pump and Schebler
carburetor.
This display has been shown at the Pacific College in Fresno and
many people enjoyed pulling the brass chain to hear the old exhaust
whistle. Also note the picture of this Cushman from the instruction
manual, showing the angle driven magneto. I suppose this was a
later model.
