I bought a Merc Poppet kit # 8030 but the diaphragm & poppet valve were different than what my motor has in it. I replaced the gaskets, grommet, spring but did not have the correct diaphragm (or poppet valve) so I am wondering if I can use the original diaphragm because when I put it all together with the old diaphragm and ran it with flush muffs. The cover (68729) vent hole spits water. I cleaned and inspected the diaphragm (64877) and relief valve plate (65664). The plate sealing lip is a bit pitted and the diaphragm has a non-smooth surface in areas around the outer perimeter (due to expanding corrosion causing "dimples in the rubber). I also noticed that as I install the assembly the poppet valve contacts the grommet before the cover & plate make contact with the block, which pushes the poppet valve as I bolt down the cover and seems to cause the diaphragm to become "unseated". Is this normal?
How important is it to have a perfect seal of the diaphragm to relief valve plate? The relief valve plate (65664) is obsolete. Can I use some silicone to seal the diaphragm to the relief valve plate? or use silicone to fill in the pitted areas of the plate sealing lip?
OPTION 2:
If this is very important to have a good seal, can I replace my relief valve plate (65664) with a design III (16497A 1) and replace cover (68729 design I) with cover (14462A 1 design III), then replace diaphragm (64877 design I) with Design III diaphragm (14479), then use the gaskets, poppet valve, water deflector that came in poppet kit #8030?
here is a link to a parts schematic 1977 Mercury Marine Mercury Outboard 1175647 Relief Valve System Diagram and Parts
