So I have a 2015 sportsman 570 EFI and recently rebuilt both the bottom and top end of the engine (new crankshaft, piston, etc.) When we tried it out we eventually heard a loud metal rattling or slapping noise on acceleration. Removed the valve cover and found the timing chain had slipped. Short version is after a couple more tries we figured the tensioner was failing so we replaced with a manual one. Same sound but chain is fine. Sound really seems to be coming from lower right engine area but am at a complete loss as to what it could be. Oil pick up possibly? Oil pump seems to be fine and no visible damage around that area. Any thoughts??