My model was made by Dettmer Industries, Inc., Waterloo, IA. It has 1.85 bore x 2.25" stroke, 9" Dia flywheels, and is 15" long by 8" wide.
"Hit and Miss" engines have a very particular sound - pop, whir, whir, whir, pop. They fire only as needed, When at speed, a governor engages a pawl against the push rod, which holds the exhaust valve open and there by eliminating intake, compression, and fuel usage. The intake valve operates by suction automatically. My model only fires once for 20 revolutions with no load. I added the air compressor, which runs steam engines to show the hit and miss firing versus a load. The green air compressor, which has an unloader, the lever at top, which turns air compressor off, which changes the firing of the JD hit and miss engine. It has an igniter, moving contacts, similar to points, instead of a spark plug. Igniter is also called "make and break" ignition, because the action closes the contacts first. Then snaps open, causing a spark.
In March of 1918 the Waterloo Gasoline Engine Company was bought by Deere and Company. For about eight years Deere and Company continued to manufacture Waterloo Boy Gasoline engines at Waterloo Iowa. In 1923 Deere and Company introduced the John Deere model E gasoline engine. They continued to manufacture this engine in 3 sizes (l 1/2, 3and 6 horsepower) until 1946 with very few and very minor changes in the design of the engine, none after 1933. The smallest and most numerous of the model E is the l 1/2HP. This engine has a 3 1/2" bore and a 4 1/2" stroke. The shipping weight is listed at 226 pounds. This engine has hit and miss ignition, an igniter, and a low tension magneto. The head was a "dry" head with the fuel mixer cast as part of the head. The gasoline tank is mounted below the flat oil pan and between the skids. The engine features an enclosed crankcase. Oiling of the engine is accomplished with an oil cup mounted on the oil pan. The balls of the governor rotate inside this cup of oil and splash oil to all parts of the engine. An improvement in this oil splash system was made to the 1 1/2 HP engine in 1933 beginning with engine #326572 The round oil cup was replaced with a larger rectangular cup and an extension similar to a paint stirrer was made onto the governor plunger to splash more oil.
The first Model E engines had a brass identification tag attached to the rear of the sub-base. After this the identification was cast in the governor cover in raised letters. The first inscription on the governor cover reads "Waterloo Gasoline Engine Company, "Waterloo, Iowa, USA" Then the Type, horsepower and RPM. Later the inscription was "John Deere" and then gave the horsepower and RPM. On the early "Brass Tag" models the serial number was on this tag. Later the serial number was stamped on a brass or aluminum tag that was riveted at the top of the governor cover above the identification. Some 1 1/2 HP engines were equipped with a spark plug instead of an igniter. These engines were sparked by battery and buzz coil. The model E was also produced in a kerosene model, which is model EK. These are scarce in this country as most of them were exported. The 3 horse is much the same as the 1 1/2 but it was equipped with a wet head and a mixer which can be removed from the head with two bolts. The 3 HP has 4 1/2" bore and 5 1/2" stroke The spark plug model is EP model. The model EP has an enclosed exhaust rod, crankcase ventilation air cleaner on mixer. The 6 Horse has 6" bore and 7" stroke, shipping weight 698 lbs. It has a priming cup on the side of the cylinder.