My Naish S26 5 M has a slow leak. It takes about 2 hours from 9 PSI to very soft but still holds shape - probably below 7 PSI. What should I do? Something like that has to be a valve leak right?

Anyone know a good wing repair in NYC? I had a guy who did kites and repaired this one when I blew it out getting through shore break, but unfortunately he said he'd never work on one again...

Spray soapy water to find bubbles.

It might not be the valve.. It's a good place to start.. by checking it with soapy water and if no bubbles appear work your way along the leading edge then the center strut till you find bubbles (and the leak).. Maybe start this process with the wing slightly over inflated.