The chain case structure for {HEAD ~ an engine} 1, wherein the reinforcement rib is disposed so as to obliquely intersect {TAIL ~ an axis} of the cylinder unit 
The chain case structure for { HEAD ~ an engine } 1 , wherein the reinforcement rib is disposed so as to obliquely intersect { TAIL ~ an axis } of the cylinder unit
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH