you've got a thru-hub exhaust if there are exhaust holes to the engine gearcase round the prop shaft. Non thru-hub is stable across the prop hub. Non Thru-hub Exhaust I might say you do have a fuel shipping https://flynnyjuz963066.life3dblog.com/29047250/how-much-you-need-to-expect-you-ll-pay-for-a-good-new-yamaha-outboard-motors-for-sale