Hello Guys. I saw your thread and thought I might provide an official answer from SLP for you.
Yes, we do recommend removing the pulley. We are concerned that the heat from the silencer may affect durability of rope. When the vehicle is running, the rope bounces back and forth and gets really close to the silencer. I don't think it would actually touch, but radiating heat could be a factor. With the wheel removed, there is no chance of heat affecting the rope. Polaris put that idler wheel there to aid in the effort it takes to pull the engine over on mornings when it is extremely cold and the sled hasn't been started yet. From our experience on the 850, the effort to pull it over (even when cold) is not an issue without the pulley.