How do you clean the carbs on a 72 bmw 75/5?

Answer 1

Before going to the expense and trouble try a a relatively new product called: 3M Complete fuel system cleaner. It's available at NAPA and Car Quest. it's meant to be poured into your gas tank with between 12-16 gallons of fuel.
It not only will clean the carburetors but also the intake manifold, intake valves and most importantly combustion chambers.
This is strong nasty stuff. Be sure you have no cuts on your hands and be careful that the entire 16 oz. of cleaner goes into the gas tank. Do not just pour it into the carburetors.
For a tad over $10.00 it's worth a try. I've used on customers as well as my own cars lately and if driven on a long sustained drive everyone seems as happy as myself. - I'm a very skeptical old man but if 3M is willing to market a product like this it can't be all that bad.

Answer 2

You should have a few things before you try this one. A manual, bucket of carb cleaner, rebuild kit for each carb,and access to air compressor. The book will give you a diagram of the carbs and basic adjustments. Do one at a time,disassemble completely,soak in cleaner until clean,blow out passages, reassemble with new gaskets and o-rings. Final adjustment take some Knowledge that will be in the book.