Ace 325 Slipping?

Hello, I have a polaris ace 325 2014 and I recently installed new 26" Zillas. Since then I have noticed and issue similar to belt slippage where the machine bogs down and comes back on. I have also heard the exhaust backfire a couple of times as well as noticing a brief check engine light. I checked the belt which seems to be fine but it has 1400KMs on the stock belt and I am slightly worried that the clutches might be glazed. I am not sure what the issue is, so I need some help. Thanks