There isn't a lot to go wrong with these carbs. Others will say there
isn't a lot to go right with them, but I found them to be mostly trouble
free with my 164.

Check to make sure the springs are the same. Often someone will stretch
them out for some reason. I tried buying replacements but found that they
didn't make the car run any better. I wound up taking some "springs"
from a pair of spiral bound notebooks -- they were matched and worked pretty
well.

Also, make sure that the diaphrams are in good condition. And also make
sure the temperature compensators are working correctly. There is a
discussion of those on a triumph web site -- they're basically bimetalic
strips that enrich the mixture; if they're different between the carbs
then things will not work correctly.

I found that once I corrected the most obvious of the prior owner's errors
with the carbs they worked okay and didn't need fiddling. What's wrong with
yours?
chris