you've got a thru-hub exhaust if you will discover exhaust holes around the engine gearcase around the prop shaft. Non thru-hub is sound within the prop hub. Non Thru-hub Exhaust Filtering fuel through a Baja filter https://elijahqrxv957744.rimmablog.com/29310815/helping-the-others-realize-the-advantages-of-shop-yamaha-outboard-motor-discounts-now