Hi guys, new here, I have a 2013 rzr 800s that i just picked up. when i start it, it has a loud rattling sound that sounds like its coming from top of the engine. Also, when i give it gas it stutters like its only running on one cylinder, almost dies when i put it in gear and give it gas. Compression test show right over 180 on each cylinder. Was told it could be a bad lifter but wanted some other opinions as to what it may be, and as to what i need to check next. Any input is appreciated. Thanks

Heres a link to a video of the engine idling.