there is a thru-hub exhaust if you can find exhaust holes around the engine gearcase across the prop shaft. Non thru-hub is good around the prop hub. Non Thru-hub Exhaust
Their naval brass spindle with rubber https://phoenixsfhk539322.iyublog.com/29216721/the-single-best-strategy-to-use-for-small-yamaha-outboard-motors