Over the years hearing people talk about the nightmare, timely, pain in the ass job it can be to change oil in a boat, when I built mine I said there has to be a better, easier, faster way to get the oil out of the pan in a boat. I came up with this; off the right rear of the pan I installed a fitting and 3/8 braided hose with a male -6 union with a cap that is mounted on the side of the block. Then I took a Chevy oil pump tapped the inlet 3/8 pipe for a fitting and a hose for the suction side to connect to the hose from the oil pan. I also tapped 3/8 pipe from the push side to some 3/8 push loc hose to shove into a one gallon clear plastic container (Arizona Green Tea) and I use either a ½ inch drill or a 3/8 drill because I made a reduced shaft to adapt to the Teflon sleeve and I can suck 8+ quarts out of the engine in 10 minutes with no mess. I have used this method for every oil change in my boat in the last two years, love it!
