Originally Posted by WayneG
It has been 6 years since I had my last rebuild, Depending on how much needs to be done, the shops backlog and your shipping method, I would expect a minimum of 3 weeks turnaround. It would be best to contact them to see what to expect for repair time. I get mine done when I take it off the road for the winter, so I don't mind if they take their time and go over it thoroughly.
There are other shops out there with fast turnaround, but you should research their quality of work.
Beware of swapping your original carb for a rebuilt, it can difficult to get an exact part number match and I have had gotten some really beat up rebuilds from retail auto parts stores.
If you go that route, keep your original to send for a proper rebuild in the future.
Carbs are generally considered wear items. So that is why I buy new. I remove carb and disassemble. This allows me to verify internals to order proper carb. Sometimes I get wrong part so I swap till it is correct.
If uncomfortable with this process, take it to an old "speed shop" and deal directly with them for advice and "service"...aaaahhhh, how I miss that word...
I would also have current one, which is hopefully original and send for professional rebuild.
Since it is hard to know if original was modified, proceed carefully.
To assist, here is place with info to help identify exactly what you have
Here is excerpt from site 2 above:
"Identification There are three basic types of QJet: the original 4M (starting in 1965), M4M (1975 onward) and E4M (from 1979). All QJets had automatic chokes, of which there are two basic types - integral (choke coil on the carb) and remote (choke coil on the manifold). 4MV carbs have the choke coil on the manifold and 4MC carbs have it on the side of the carb in a housing. An M4MC carb has a choke coil on the carb; and M4ME carb has the same type fo choke coil, but with an electric heater element in the choke coil.
Choke parts, primary metering rods and throttle shafts are not interchangeable between 4M and M4M carbs."
Obviously rebuilding by professional is ideal.... Just floating options...