my viz freewheel used to skip too(maded by the same factory with monty's), that's because i often wash my bike my bike with water,and didnt dry it as soon as possible.the water in the freewheel made it rusted.so i washed my viz with some gas of my motobike and then a little lubricating oil(don't use too much) ,now it is better.i will never wash my bike with pipewater