Can I get the model number for my Consew by having the serial number I can't find a model number anywhere

Older Singers generally do not show the model number--the Serial number determines the model.

Serial Numbers Comprehensive Singer Sewing Machine Serial Number Database

The serial number could be located anywhere. Usually it is stamped into the metal--look at the back of the machine or even underneath. Note--older Singers do not have model numbers, only serial numbers.

This may help you learn more about your machine when you do locate the serial number:

Singer Sewing Machine Company Serial Numbers

...

google it make/model/ that number .

There are several sites that all offer a number of Consew manuals; none for the 166 or 166r.
You might fine a model number that is close to yours and see if it looks like yours.
http://www.tias.com/cgi-bin/search.fcgi?lc=1&database=%2Faltavista%2Fstores%2Fitems&itemDatabase=%2Faltavista%2Fstores%2Fitems&store=%2Fstores%2Frelics&resultPageTemplate=ResultPage.html&resultItemTemplate=ResultItem.txt&noResultPageTemplate=NoResultPage.html&case=no&minPrice=&max=20&matchAll=0&bothSearch=1&searchText=Consew

http://www.sew4less.com/index.php
I don't know if the link will work for the bobbin case, if it doesn't
go to sew4less.com
Bobbin Case # 52237 NB, Click for model info.
Product #: 4754

Price: $ 19.95


Bobbin Case # 52237 NB, No backlash type.
A bobbin case, also known as a bobbin holder or bobbin shuttle, holds the bobbin that is filled with thread.
Each machine has a specific bobbin case. # 52237NB
Brother 755 Brother B714 Brother B735 Brother DDL-227 Brother DDL-555 Brother DL-5550 Consew 103 Consew 104 Consew 210 Consew 230 Consew 231 Consew 7360R Consew 99 Consew CN 223OR Janome / New Home 764 Juki DDL-227-L Juki DDL-5530 Juki TL98E Kenquilt 622 Singer 1300 Class Singer 1400W Singer 188K Singer 191U Singer 195K Singer 196K Singer 241 Singer 245 Singer 251 Singer 281 Singer 291U and more!

here are is a site that have manual
http://www.sewingpartsonline.com/

I have an instruction Manual for that machine if you would like it you are most welcome.

Hi
There are free threading diagrams available here.
http://www.sewusa.com/Sewing_Machine_Threading_Diagrams.htm
I couldn't see your model number listed but have a look at a few of the diagrams for other Consew machines to see if they are similar to your machine.
Hope this helps!

Wawak has the cases. You just order by your machine model #.

Go to www.consew.com. Click on the model number of the machine. Click on "owners manual" and download it. It's a pdf file with pictures.

Go to www.consew.com. Either send an email or call them. They're very responsive to questions.
I have a 226R-1, my second one. Both of mine were built in Japan and are/were at least 2- - 30 years old. I think current models are made in China. Serial numbers are under the bed on the front side of the bed.