Sorry Jonez, I had not noticed that the two fuel pump diaphragms for WTs were of different designs. Your old diaphragm has stretched to a saggy/baggy condition and I would not re-use it. In that situation I would certainly use the mylar diaphragm. Just be careful to fit it correctly, it is a lot thinner and more easily wrinkled/folded/ creased than the conventional type. With correct fitting I'll be surprised if it does not work properly. Please let us know how it goes of course - I don't recall a thread featuring a mylar diaphragm, so a lot of people will be interested in your experiences with it.
