LUBRICATION AND ADJUSTMENT OF BEARINGS 53 



set-screws and tightening the cap-screws will leave the 

 shoes free to run and with no lost motion. When the en- 

 gine runs "under," as in threshing, the wear is mostly on 



FIG. 15. THE CROSS-HEAD. 



the upper shoe and guide, and when engine runs "over," 

 as on the road, the wear is nearly all on the lower shoe and 

 guide. Usually the wear being nearly the same on both, 

 they should be set out equally. The wear is slightly 

 greater at crank end of guides and if the shoes are adjusted 

 so cross-head is free at cylinder end, it will not be too tight 

 at the other end. 



The Eccentric Strap is tightened by removing the paper 

 liners. When these are all removed and the halves come 

 together, they should be taken to a machine shop and a 

 little planed off. The eccentric-strap must be well lubri- 

 cated at all times, preferably with cylinder oil. The eccen- 

 tric rod brasses and valve-rod brasses on engines having 



