Just ran a search on chainsaw thread and it worked fine.
I have found that with the extensive database to search that sometimes with heavy site traffic it will time out.
Helps to narrow search terms down if you can. Can narrow down by time frame and by user name which helps a lot.
To search all posts with a broad search criteria you may need to select a couple years at a time as the time frame.
I mostly search for stuff I have posted previously about so when I add my user name as a search parameter that helps narrow things down a lot.