I picked up a 2018 Polaris Sportsman 450 EPS with only 145 miles on a trade. The thing looks practically new, but it runs and drives rough. Engine makes a screeching noise st idle and when starting to drive slowly it gets really loud. The seller said he thinks it need the bottom end rebuild. It only has 145 miles on it. Could it really need a new bottom end at only 145 miles? Any suggestions on how to diagnos this? Has anyone had to replace or rebuild a bottom end on a new ATV? Any idea what could cause a bottom end issue on a new ATV? I'd greatly greatly appreciate any advice. Thanks!!!!