Re: 1988 mariner Magnum2 150hp ?
It's probably been awhile. I got the boat about a month ago so the boat needs some tlc. I plan on doing the repair on my own is there anthing else I need to know before I take it apart and what is the cost for the poppet diaphragm?
If you have to ask, you can't afford it.
Seriously, poppet and water pump parts are nominally priced. The failing part is the diaphragm. I'd get 2 gaskets, the diaphragm, the poppet valve, and the grommet. In a parts listing, the pressure relief valve (poppet) is usually on the exhaust plate page.
You need to pull the LU and the water pump. At least the impeller and housing gasket needs replacing. If the wear plate is grooved, it and the gasket under it also need replacing. If the housing is worn or warped from either heat or improper installation (over torqued) it also needs replacing. The water outlet seal and the slinger washer should be replaced if they have hardened or cracked with age. After you look things over, order your parts.
Before you drop the LU, take out the oil drain plug and catch the first few drops out of it. You can put the plug right back in, you don't have to totally drain it at this point. If there's any water or milkiness in it, have a good mercury shop go through the LU, replacing all seals and any bad bearings, and setting up the clearances. This could be pricey, but not nearly as pricey as a new LU. Well maintained and oiled, and driven properly these LU's will last a lifetime. Neglect them and they will let you down.
