Reply To: KG7 Water pump replacement

[George Emmanuel]

Personally, I have no use for a Mercury. But, with that said, one needs to understand why those w/p covers are so hard to remove. It has to do with the threads of the disc. Aluminum will easily gall. When those discs were made, the threads were rough, which didn’t affect it going in, but, as you try to back it out, the burrs in the threads will try to reverse position, and when they do, they act like anchors. Imagine a water pump impeller. As it turns, the blade curve backwards and take that position. If you try to rotate the impeller the opposite direction, the blades will act as a brake. The same holds true for the burrs on that disc.

Before you install a new disc, rotate the disc in some 320 grit, or close, wet/dry sandpaper to remove the burrs. Then clean the threads well before you install. It should screw in easily,–if not, clean them again.

George