1980 Evinrude 175

" Water is running out of a sm

" Water is running out of a small hole located at the top of the left cylinder head. The hole is located just above the spark plugs on the left side. The right side has the same hole but no water coming out. Also, at the end of last season my over heat horn would go off at high speed. "

"Craig.... That hole is a pres

"Craig.... That hole is a pressure relief hole which allows the water bypass diathram to operate in and out. The leakage is caused by either a salt build up on the diaphram or a corroded area upon which it seats.

Remove that cover and the diaphram and check the metal seating surfaces. If the sealing surfaces are eaten away, you'll need to correct that. Hopefully they're okay as usually a corroded surface demands the replacement of the cylinder head.

If the surfaces are okay, clean or replace the diaphram(s). To insure a perfect seal, coat the outer edges of the diaphram(s) with Marprox Sealer 1000. You may find this same substance under the brand name of Boat Armor, but the tube will always state Sealer 1000. This sealer should be available at any automotive parts type store.

The warning horn going off at high speed would indicate that the water pump is weak and failing.

Joe "