Thanks for the replies - I forget to look in this forum!
Indeed, it's a C90 on a permit. I'd been trying to get it to the Rally but looks like too many issues and it all won't get done in time.
It's a long story, but the carb was removed by a maintenance org. because of rough running at high revs/carb heat and sent off to be checked.
I've discovered the cause of the rough running (cracked exhaust under the carb heat shroud feeding exhaust gases back into the carb), but the people who looked at it sent it back beyond economical repair because it has a 2 piece venturi which it seems is subject to AD 98-01-06. Linky here:
http://rgl.faa.gov/Regulatory_and_Guidance_Library%5CrgAD.nsf/AOCADSearch/9F87A5E42C10900C86256A410065C0CD?OpenDocumentThis states:
"If a two-piece venturi is installed, inspect the carburetor at each annual, 100-hour, or progressive inspection, to determine if the primary venturi is loose or missing. If either of these conditions is found, prior to further flight, repair the carburetor by installing a serviceable two-piece venturi or by installing a one-piece venturi in accordance with Precision Airmotive Service Bulletin (SB) No. MSA-2, Revision 1, dated November 11, 1991, Revision 2, dated December 28, 1993, or Revision 3, dated October 10, 1995. Installing a one-piece venturi constitutes terminating action for the repetitive inspection requirements of this paragraph."
The carb lookers were looking at the work to convert it to a single piece venturi and make the other changes as necessary. This makes it uneconomical apparently!
But the AD seems to suggest that the 2 piece is fine as long as it's inspected annually or every hundred hours.
Am I reading it right? Are the carb people just trying it on? I don't see the need to a new carb?
Thanks!