I've had this issue for years - I've tried rebuilding the search index several times, plus IPB often does this as a background process when a new version is out but it does not fix the issue.

My problem is I can't search for the word looking. I've checked in SQL & there's tonnes of results:

SELECT * FROM `ibf_forums_topics` where title like '%looking%' returns 275 threads

SELECT * FROM `ibf_forums_posts` where post like '%looking%' returns about 17k results.

Is there any setting I may be missing which might be restricting certain words from being searched?

You have to remove "stopword" in .cnf file in mysql at your server.

ft_stopword_file = ""

and restart server and rebuild search index again.

http://www.nivas.hr/blog/2009/09/15/how-to-disable-mysql-fulltext-stopwords/

At my site there is no problem to search word like that.

51 minutes ago, jcdesign said:

You have to remove "stopword" in .cnf file in mysql at your server.

ft_stopword_file = ""

and restart server and rebuild search index again.

http://www.nivas.hr/blog/2009/09/15/how-to-disable-mysql-fulltext-stopwords/

At my site there is no problem to search word like that.

Lifesaver! All this time I was blaming IPB thinking the search function was rubbish, and it was my own incompetencies in server administration. 

Thanks so much - working perfectly now, even for 3 letter words too! 

That´s great! 

I've logged this as a ticket also - but has anyone else noticed that when you do a search & have it set to all content, started on any time, last updated on any time, it still only returns results from Jan 1st 2016 to the present?