I have a 2015 Sportsman 570 EFI (1,110 miles) and had this same noise. Removed the transmission to find the chain tensioner was at its max. The pins that connect the links of the Silent Chain wear which causes the chain to be longer. When the tensioner can no longer keep the chain tight, the chain slips on the 19T sprocket. This is what is causing the loud popping noise. The factory replacement is 3234057 and is $140-$200 depending on where you get one. My problem is I am trying to find an aftermarket alternative. The chain has 86 pins and is 11 plates wide. Any thoughts or part number on another chain that will work?