The clutch does not disengage easily. There are two main reasons, one is the free stroke of the pedal is too large; The second is improper separation lever adjustment. Both of these causes can lead to incomplete clutch separation. The transmission often jumps gears. There are three main reasons. First, the positioning spring of the fork shaft is weak or ineffective; Second, the wear of the positioning slot of the fork shaft exceeds the limit; Three is the transmission of internal and external spline wear lead to gear and shaft do not match, can not synchronize, so the phenomenon of jump gear.