no more leaky petcock

I finally got around to rebuilding the petcock on my bike last weekend. Get it all done and filled up the tank with gas, and low and behold it leak worse then it did before. :blink:
I was searching the forum on the issue and saw the one on the Suzuki petcock, and was about to order one from Z1, when I started to study this spare I had sitting around. Then it donned on me that the rubber diaphragm that mated to the petcock body was no different then the gasket of a diesel fuel filter, in which you have to put a film of oil on or it will leak like a sieve.
So tonight when I got home I emptied out the rest of the gas and took the petcock apart again, and applied a oil film as in this picture.
Final result was a perfectly dry petcockB) :woohoo:
I hope this will help anyone else out there trying to deal with petcock leaks.
Bill.