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FARM MOTORS 



in Fig. 257. Having done this, find the point E, midway 

 between the two marks on the flywheel, and make a 

 punch mark there. Turn the wheel until the tram drops 

 into this mark (Fig. 258), and the engine will be on dead 

 center. To find the opposite dead center do likewise or 



FIG. 257 



FIG. 258 



measure half around the wheel. When it is inconvenient 

 to measure on the flywheel, the crank disk can often be 

 used. 



522. Setting the slide valve. To set the slide valve, 

 remove the steam chest cover and put the engine on dead 

 center. Turn the eccentric on the shaft until it is 90, or 

 a quarter of a revolution, ahead of the crank in the direc- 

 tion the engine is to run. Now a'djust the valve on the 

 rod until it is at its center of travel, then again move the 

 eccentric ahead, this time only until sufficient lead is ob- 

 tained. Fasten the eccentric to the shaft and tighten up 

 the lock nuts on the valve; then turn the engine over to 

 the other dead center and see if both sides have the same 

 lead. If the lead is the same in both ends, the valve may 

 be set. If there is more lead in one end than the other, 

 move the valve on the rod an amount equal to one-half 

 the difference. If now the valve has too much or too 

 little lead, the eccentric should be slipped forward or 

 backward, as the case may require. 



Moving the eccentric in the shaft increases or dimin- 

 ishes the lead, depending upon the direction it is moved. 



