Turning off recusion

[churchers at gmail.com]

We have 3 nameservers which are now authorative for about 1000 domain
names and have,
unfortunately, been historically used as general purpose resolvers.

I would like to turn off recusion but if I do, they start reporting any
domain name they don't run dns
for as being non-existant.

--
pegasus# ping www.google.com
ping: cannot resolve www.google.com: No address associated with name
--

Shouldn't they be referring the lookup to parent nameservers or am I
missing something?

I don't want to break the ability for the server itself to be able to
resolve hosts. If this means
leaving recusion on, then i'll have to leave it as it is.