How do I improve the water output from my Mariner 20 outboard 2 Stroke?

If the water out stops, Your pump is not fine. Depends on how you get the water to it, is the outboard leg submersed when trying, or are you using muffs. If submersed, your pump is bad, if using muffs check they are tight on side, enough water available for the pump to pump. If no water comes out the sides of the muffs, again your pump is not fine.

Sheepdog
March 2011