"Extra" Fuel Pump Diaphragm

[cmayhle]

I have a 1976 Merc 500, 50 that I have purchased (2) Integral Fuel Pump Type diaphragm and gasket kits for (Part #5137). In matching up the pieces to those existing, I find an "extra" nylon piece that exactly matches the profile of the rubber check-valve diaphragm. Could anyone tell me where this piece gets installed? I don't see a corresponding piece in the existing fuel pumps, nor is this component listed or shown on the exploded shop manual drawing. Thanks kindly

[boats.net]

Those kits are used among many models, that part may not be for you model.

[cmayhle]

Those kits are used among many models, that part may not be for you model.

Thanks boats.net, very helpful!