528 



Farm Mechanics. 



at M in Fig. 257 where the upper K is the valve stem 

 which also works the gasoline pump. 



662, Valve Mechanism. The supply and exhaust valves 

 for the engine of Fig. 256 are represented in Fig. 258 and 



FIG. 258. Valve mechanism of gasoline engine. 



are located in the chamber A of Fig. 256. The upper 

 valve A is the exhaust and is represented forced down so 

 as to open the port, allowing the burnt charge to escape up- 



