I'm putting a 70-something Mercury 1500 on my boat, and I'm thinking about using the jet pump that came with it instead of a lower unit. I know nothing about them. Can I start the motor out of the water with a pump? (on the hose) What do I need for shift linkage on this pump? (See picture, I'm not sure what's missing) What is the little U shaped piece of rubber hose for on the top of the pump?