When cutting the yard the mower works great except when I cut the back corner of the yard there is a hill. When cutting up the hill about half the way up the mower will let out a big cloud of smoke. And I do mean big, it will also act like it is going to quit but just for a second. After that it runs fine for the rest of the yard till I go up the hill again. The mower is a zero turn and is only about two months old. (My sons mower). Sure could use some advice on this. Thanks for any help.