I just bought a rebuilt Rochester Model B that has a small hole drilled in the air horn. I was assuming that the hole should not be there until I ran into this on ebay:

http://cgi.ebay.com/ebaymotors/ws/e...=4504440863&rd=1&ssPageName=WDVW .

It is a Model B with the same hole drilled in the horn that my rebuilt one has. Please look at the upper left photo of the left side of the carb to see the hole drilled in the air horn below the choke shaft. Does anyone know what the holes are for?

Thanks for your help.

Jon