I had a new rear tire put on my 220 KDX yesterday. A Dunlap 756 in the 110/100-18 size. I had a brain cramp when I was at the store and could not remember what size to get. When I put it on it looked a little big but seems to fit OK. I read the manual a little late and the stocker is a 100/100- 18. Should I take it back or run it? Thanks