i tried to post a link to the manual has all the original part numbers to the engine for the W1-185 motor, including carb, but the forum replaced the text with "hahahahah" etc... i tried to upload the pdf but it was too large, if the link wont work i can email it to you... if you havent already downloaded it...
found on a website called jacks small engines dont know if they carry the parts, but they had the parts manual uploaded into their database to make it easier to order...
found several apparent chinese clones of a carb for a wisconsin robin engine... not sure if the parts are interchangeable (if you want to use the original and not a clone)... sorry was bored and decided to do some searching...
http://www.ebay.com/itm/WISCONSIN-R...arden_GardenPowerTools_CA&hash=item1e67f19ac5
but i checked the original part number and it is different... this is the only type offered on fleabay...
the original part number out the winconsin robin w1-185 manual for the carb is EY 2276230200, main jet is EY 2276240008
in the manual it does seem to have some specs on certain screws for instance "SCREW, choke valve mounting . , . . . M2.6 x 0.45 x 4 mm long, pan head", maybe some of those numbers could be of use too?