I just bought a new rear tyre that is 110/90-19 I should have got a 100/90-19 it was my fault ordered wrong one but would it be ok to put the 110 on my Yz 125 97?
you will probably find a loss of power on a 125. More tire to turn and more rubber on the ground. It will fit but probably won't be happy with it. I would take it back to a shop and see if they will trade you for the correct size.