Having trouble building water pressure on 70 hp mercury at full throttle I am getting 7psi and it is fluctuating on the guage. What pressure should I expect to see out of this motor? I have replaced the waterpump and when I slide lower unit back up I have trouble getting the water pipe into the waterpump. The water seal keeps getting hung up in the water pump and does not allow the pipe to slide in. Is there a trick that I am missing I am lubricating the pipe and seal. Thanks to everyone in advance.