Hi
there's free White overlocker/serger manuals via the Singer website, strange as it may seem.
Look under Singer's "Support and Resources" then select "Instruction manuals" , or
follow this link:
http://www.singerco.com/support/instruction-manuals
On the Instructions Manual page you'll see it says "Find Your Manual - Step 1, Step 2 etc etc" and under that there's a search box that says "Model Number"
Into this search box just type "w"
(don't type "white", because that doesn't work)
You'll be taken to a near incomprehensible results page but
scroll down and you'll see one listed as "WSL234d, WSL234DE" Just click the button "Free download" to the right of the lists, and it will open a PDF file of the manual.
Good luck, and I hope you find what you need :)
Kind regards
Kura
Instruction Manuals