Help! Vacuum piston malfunction

[JERRYB]

Any one have any idea on how to reseat the vacuum piston on a Keihn CVK carb?
My 94 kawasaki was leaking fuel from the float bowl so I thought a new float needle would helpout, as I had the complete kit figured might as well renew all--wrong--spent 2 hrs trying to get vacuum diaphragm back in the groove, really do not want to put out $140.00 for a intact diaphragm. It seems like the diaphragm is stretched?
Thanks

 

[doorfx]

If you put the diaphragm in the freezer for a couple of hours it stiffens up and is a lot easier to get back in the groove. Works great

 

[JERRYB]

Thanks!, Will give a try tomorrow.

 

[JERRYB]

Update:
Happy to report that suggestion by "doorfx" worked, set diaphragm outside for a couple of hours, (was 5 above zero F) was able to secure and seal, running again!
Thanks again Doorfx!