This oil drain kit allows draining of engine oil through the oil pan drain plug.. Includes special tether so oil drain hose can be pulled out through the boat bilge drain hole to drain engine oil. Boat needs to be removed from the water to take advantage of this feature.. Fits the following models:. 1983 & newer MerCruiser Marine GM 4 cylinder. 1995 & older MerCruiser Marine V-6 & V-8 engines (all, except 8.1L) with standard (SAE) 1/2-20 oil drain plug threads