How to replace text in sql server 2000 in a ntext column with more than 4000 characters? conversion to nvarchar(max) does not work as it truncates values.
Working with TEXT/NTEXT is a mess - one of the many reason to get rid of those fields as quickly as possible.
You need to manipulate those with command such as READTEXT, WRITETEXT, UPDATETEXT and other - see some resources for help: