This is the 2017 model, 13AX79BT011. I spent a good few hours messing around troubleshooting before I figured out it was the belt. Even though it was not stretched or broken it was worn on its face so it was not gripping the pulleys. I went and bought the OEM transmission belt (954-04252) for $33 and now it goes faster than ever.
![](https://i.ytimg.com/vi/R6CI9BDLWII/maxresdefault.jpg)