Well lets look at this logically. If the razor is not defective you have ruled that out. If the bevel was properly set and you could shave off the 4K you were on your way. If failure happens after the 1K and the bevel looks great then go back to the 4 or if it shaves but on the 8 you can't make an improvement go back to the 8. There are no demons in a Dovo they hone up pretty straight forward so I suspect the factor is you.