Mercury - Rear Cowling Decal Set for 3.4L V6 175HP Pro XS Outboards Cowling Restoration Kit Factory-Matched Marine Graphics 8M0214850. Overview. Every boater has a moment when they glance back at the motor - maybe while drifting in the morning calm or trimming up before a long run - and feel that quiet pride that only comes from owning a Pro XS. These engines are built to perform, to leap onto plane and pull steady through wind and chop. But the cowling takes a beating along the way. Sun, spray