MZ/MuZ Riders

http://cgi.ebay.com/ebaymotors/KEIHIN-F ... 0225300018

Seem to be the right ones for the 660?

I hope one of our Euro Gurus chimes in, but if I'm not mistaken, those are exactly the Keihin carbs that will fit the Baghira (and apparently improve performance greatly). When I decided that the Keihin or Mikuni FCR 39 are the carbs that will REALLY help my Baggy out, I prepared myself for a pretty big expense, but I hope I don't have to dig into the wallet for $750+ for those babies.

Before bidding on/buying those, I'd check with these folks: http://www.bikeworx.com

They are reputed to be very trusted distributors of Baggy parts AND knowledge, and would likely get you those carbs for a fair price (which might be $750, I don't know).

MSW

the Keihins are very good, BUT way too big unless you have done serious reworking to the cylinder head:

and done the usual: Megacycle+Kibblewhite or RD, Carillo, JE piston+rebore, much larger headers etc. etc. etc.
The carbs are expensive but nowhere near what the tuning itself will cost.
If you are running the stock engine+exhaust system, anything bigger 34 or 35mm ist simply too large for the manifold vacuum. The beast will not be drivable.

Use the search engine and read what Wonky has written, and what I have written as well.