Fuel pump check valve

[Jtsarby]

I got a rebuild kit for my fuel pump. The check valve that is in the fuel pump now is very thin plastic. It looks similar to the one pictured but is is thinner and more flexible. The kit had a thicker plastic valve and a rubber one. The instructions show the rubber one goes with a smaller plastic disc to keep the rubber valve from coming off. The larger plastic one in the kit seemed too rigid to operate correctly so I reinstalled the original thin plastic one. What should I have done? Here is a pic of the two that came in the kit.

[JOE54]

plastic, you got an aftermarket kit didn't you , run it for a while and find you a genuine merc kit , I do not like those, why diaphrams are thinner low quality