KEEWAY FACT 50 4T Maintenance Manual page 149

Remove the oil seal from the left crankcase.
Oil seal
Check
16.3.2
Measure the left-right clearance of the larger end of the
connecting rod.
Limit for use: 0.3mm.
（连杆大端测量位置：measuring point at the larger end of the connecting rod）
Measure the clearance of the larger end of the connecting rod
(X-Y direction).
Limit for use: 0.018mm。
Check whether crankshaft bearing makes noises or is loosen
when it rotates.
If yes, replace the crankshaft assembly.
149
Crankshaft bearing