tilloston carbs?

Well i bought an intake with 2 tilloston carbs model yr2. Anybody know anything about these carbs. They look complete and are free and all parts move

 

Everything I've read is the Tillotson was a replacement carb sold cheaper than a rebuild kit cost for most original carbs. I've seen the downdraft ones in good shape bring $30 or so on eBay in really nice or NOS shape.

 

Are they 2 barrel or 1? I've got a couple of the 3 bolt 2 barrel replacement carbs.
Clark

 

one barrel. They are in good condition though for lieing in a garage for 20 years.

 

From the little that I know, they were also used on 2-stroke snowmobiles.
Seems like the '74 (or so) Yamaha 246/292 snowmobile that I used to ride had a Tillotson carb on it. It had the "fuel pump" built into it - a diaphragm set-up.

Malcolm