Just installed a Kurts gear down on a '19 850 Pro. We had to grind down the casting on the forward edge. Maybe 1/16 to 1/8". Not much. And while no contact, we also ground out a small part of the battery bracket for peace of mind.If anyone is running e start with the qd2, you will have to grind the battery bracket down a little bit as I noticed it rubbed my belt a bit.