I have a 2003 Sportster 150 with a 155hp non supercharged engine. I’ve seen in a few videos where guys hook up a hose to somewhere on the back of the boat and circulate antifreeze throughout until it come out the exhaust etc. I understand what they’re doing, I’m just trying to make sure of where they’re connecting a hose at the back of the boat. It appears there’s about a 1 inch pipe coming out the back at about 10 or 11 o’clock when you look at it from the back. I usually try to do maintenance on everything myself and this is the first fall I’ve own one of these boats.