hydro tranny question
 

Hi all, i have a chance at a newer cadet can't tell in the pics if it is a 1120 or a 1720 and can't get pics to load. problem is that when it gets warmed up, the tractor won't back up. i've never had a hydro and if its' not an easy fix, i guess i'm out. any ideas? also, what engine would this have?