15T front sprocket. Bike is happy.
.Hard to say on the temps as the spark plug temp gauge may not be representative of the oil temps. I did read somewhere that there was a 30f drop on the Grom system, so I bet its pretty close to that. Install was fairly easy...I'm not good at reading foreign languages, but its pretty straight forward. Looks pretty cool too. These are quality pieces. Will know more about any temp differences on the daily commute this coming week. Will post anything of note then. All the items were purchased from Hard Racing.