Merc 115 Water Pump Question

[gman1001]

Thank you! Seemed to work well - the unit has been put back together nicely. How do you know the fins of the impeller are correct however? I lightly greased the impeller cup and after having put it back together I can turn the drive shaft with one hand but its not easy.

Funny I bought the official Merc manual for this Straight 6 motor thinking this procedure would be included. Nope!

Again thanks for your input - very much appreciated as its obvious you know what your talking about!