How to Clean Gummed Up Carbs

Updated April 17, 2017

If the carburettor on your old car or motorcycle is gummed up, you don't have to stop driving it. Over time, especially with fuel sitting in it, a carburettor can develop a layer of varnish wherever fuel sits. Cleaning off this layer of varnish, and opening up fuel passageways, may be easier than you think. With a little mechanical know-how and some basic tools, almost anyone can revitalise a gummed up carburettor and breathe life into a vintage ride.

Remove the carburettor from the air intake manifold.

Disassemble the carburettor noting the position of all part elements for reassembly.

Remove any rubber, felt or paper gaskets from the carburettor even if they are in good condition. Chemical carburettor cleaners will damage these gaskets.

Soak all metal parts in liquid carburettor cleaner. Allow the carb cleaner liquid to have access to all passageways inside the carb by rotating and shaking the part while submersed in the liquid cleaner.

Remove the parts from the liquid cleaner and blow dry using compressed air. Ensure all passageways are clean and free of any cleaner residue.

Replace all rubber, felt and paper gaskets with new replacements. Even if the gaskets look to be in good condition, it is best practice to replace all of them at this stage to avoid having to disassemble th carb again.

Reassemble the carburettor in the opposite order of disassembly. Reinstall the carburettor using a new gasket over the air intake manifold.


Check that all small holes are free of any gummy fuel residue before reassembly. If any springs or other parts are worn, replace with new parts obtained through your local auto supply store.


Wear protective clothing when working with carb cleaner. Do not to allow it to contact your skin or eyes, as it is corrosive.

Things You'll Need

  • Liquid carb cleaner (1 gallon)
  • 1 can of compressed air
  • Replacement o-rings and gaskets
  • Tools (specific to your vehicles make and model)
Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

Brandy Alexander began writing professionally in 1993. She has years of experience as a professional of the English language employed with the "Cape Times" and "The Mercury." Alexander holds a master's degree in English literature from Stellenbosch University in South Africa.