Old carburettors are problematic (or can be); they wear internally, with a coat of "varnish" being deposited over the years on the inside surfaces making them difficult to balance, leading to sub-standard performance and poor starting.
In an ideal world, you would simply fit brand new carb assemblies. But, the world not being ideal, the cost of NOS (new old stock) carburettors can be prohibitively expensive; assuming you can get hold of them?
The realistic and much cheaper alternative to new carbs is to strip the old items, getting the internals sonically cleaned, and the bodies vapor blasted to restore a pleasing finish.
This can be complimented with new internal and external components like diaphragms, valves, jets, air screws and springs, plus any other parts that are worn, damaged or corroded, both for sound mechanical and cosmetic purposes.
You may also wish to check out the carb related components listed below:
Order new gaskets 1325844B00 and seals 1355644B00 1350917C00 1337446710 at the same time? This component may have other applications within the Suzuki model range - so please ensure you order the correct part-number for your model.