WUR inlet fitting question

[1980sel]

Hi guys just a quick question...on my 1980 450sel the inlet fitting on my wur has some kind of tiny strainer in it..and its very restrictive...I'm about to replace my wur...should my fitting have a strainer in it???

[s class]

Yes, to prevent debris from upstream entering the metering orifice of the WUR. 

The restrictiveness of the filter isn't a problem, unless its blocked.  Remember, the flow rate through the WUR is very low.

[1980sel]

Ok I was just making sure...seemed like too many filters with the ones in the wur itself..I'll just clean it and leave it in place. I do have another question...the other night while trying to remove the inlet fitting I ended up turning the whole top piece that it threads into...I postioned it back where it was but ever since then my wur has not been the same...rich on cold start...now granted it wasnt healthy before this happened but what damage could have been done by the whole piece turning??