Re: 90hp mercury water pump problem
Peg, You have really confused me now. There is a single copper watertube the connects to the water pump cover and supplies the motor with cooling water.
Just so you know, water from the lake enters the waterpump base from the bottom thru the 4 holes on each side of the geracase, just above the bullet shaped part of the gearcase. The impeller runs in a non-circular chamber, which causes it to be pumped up the water tube.
The driveshaft is supposed to be splined to the impeller, so it turns whenever the motor is running.