When the crank seal are bad, the oil leak and create a hydro lock when you want to start the engine. I added a shut off valve 2 years ago to close it when not in use. I never had any problem with hydrolock after. This modification allow me to use gear oil with is thicker than the expensive Seadoo oil. The benefit will be that the oil will drop less than the 2 strokes oil and it’s cheaper to fill it up. Some other guy just loop the lines together but I felt it was a pain in the ass to fill it up. With my little reservoir it will be easier!