ENGINES, MOTORS AND TRACTORS 747 



other legitimate cause. It should be remembered by all who operate 

 gas engines that oil is cheaper than iron. 



The gravity system is the most common means of lubrication. It 

 consists of a glass cup placed above the highest point to be lubricated. 

 The splash system is very often used and consists of a crank case filled 

 with oil to the point that the crank touches the oil at each revolution. 

 The force feed type of lubrication is very successful; however, it adds a 

 few more working parts to an engine, which complicates and may cause 

 an added trouble. There are other systems of lubrication which will not 

 be mentioned because of the infrequency of their use. 



Gas Engine Parts. — The base of a gas engine supports the cylinder 

 and all other parts of the engine structure. It should be in proportion 



-4 



it 



Three H.P. Gas Engine Operating Binder. 1 



to the rest of the engine. The cylinder serves the purpose of a container 

 and a receiver. It should be smooth and free from irregularities or dark 

 spots. The cylinder contains the piston and receives the charge and its 

 walls receive the force of every explosion. The piston transmits the 

 power to the connecting rod which is similar to the pitman of a mowing 

 machine. The crank shaft receives the sliding motion from the connect- 

 ing rod and changes it into rotary motion. 



Governors. — There are two distinct types of governors used in gas 

 engine operation at the present time. The hit-miss governor causes the 

 exhaust valve to be held open mechanically when the engine begins to 

 run above speed. So long as the exhaust valve is held open fresh air is 

 drawn in and blown out; therefore, no power is obtained. As soon as 



1 Courtesy of Fairbanks, Morse & Co., Chicago, 111. 



