Triumph Repair: TR6 CARB, air valve, car need

Question
SCOTT...I JUST BOUGHT A 72 TR6 THAT WON'T RUN RIGHT UNLESS CHOKE IS HALFWAY OUT...TOOK IT TO A LOCAL CARB GUY...HE REBUILT THE FRONT CARB FIRST...WHEN HE WENT TO DO THE REAR ONE, IT TURNS OUT THAT THE REAR ONE IS A "NON-ADJUSTABLE" CARB...I GUESS FROM AN EARLIER YEAR. WHAT DOES IT TAKE TO CONVERT THE NON-ADJUSTABLE ONE TO AN ADJUSTABLE ONE ??? JUST THE METERING NEEDLE (3-631 MOSS ?) HE SEEMS TO BE HAVING TROUBLE REMOVING THE NON.

Answer
You may have to replace the air valve with the needle on the rear car to get the right setup.
You may look for a used CD175 with the needle you need, may be easier to source than just an air valve.

With needing the choke 1/2 pulled, likely all the settings and timing on the car need to be done to get it to the right conditions.