The green material is what Mr. Asa was referring to, nitrile gloves cut to size, bought off eBay. Ken W. originally made that suggestion and used it himself and worked well so I tried it. I’ve also have had a piece of it sitting in ethanol gas for about 6 mos. with no problem.
The plastic piece was an idea from Frank Robb…"you can use the diaphragm and diaphragm support from a 393103 kit (Sierra 18-7820)." I’ve used that and also pieces like the picture below from eBay. 304094 is actually the little metal disc that is used in that fuel pump. If you use 318375 just cut of the stem.
I think this is a good way to keep these pumps in service, whether you use the nitrile or real diaphragm material. They’re simple and easy to work on and rebuild (as long as you don’t have to make the hard to find front gasket), and they pump just fine.
I think there was a concern mentioned about the spring sliding out of position using a support/cap like these. The original riveted support has a raised center that I think was designed to prevent that. But these supports are curved around the edge and I think that once everything gets squished down there’s not enough "wiggle room" for it to go anywhere. At least the 3 I’ve done so far are holding up. Of course, your mileage may vary.
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