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How to Repair Aircraft Carburetors

Repairing aircraft carburetors generally involves cleaning them out and replacing their various jet parts and gaskets. This tends to be the easiest method by which to solve carburetor mechanism problems, both known and unknown. Because the units involve parts screwed into a cast assembly unit that creates a Venturi effect of fuel and air, any major repair involves removal of the unit from the engine. Fortunately, carburetors can be disconnected and reattached fairly quickly, so this does not involve much work.

Things You'll Need

Socket wrench
Crescent wrenches
Screwdrivers
Carburetor rebuild kit
Cup

Instructions

- 1
  Lift the engine panel covering the assembly to expose the carburetor. Loosen and detach the carburetor from the engine intake manifold with a crescent wrench or socket wrench. Pull it loose and remove the fiber gasket.
- 2
  Disconnect the throttle cable from the top of the carburetor. Use a screwdriver to loosen the clamp on the fuel line. Pull the line off the unit and pinch it off. Pull the carburetor unit out of the airplane engine cavity and place it on a workbench.
- 3
  Loosen the air-filter component, using a screwdriver. Remove the filter from the carburetor. Locate the various outside jets of the carburetor ̵2; the idle and pilot jets. Use the screwdriver to loosen and remove all of them from the carburetor body. Place them in a cup for safekeeping.
- 4
  Remove the float bowl unit from the bottom of the carburetor with a crescent wrench. Use the screwdriver to loosen and remove the main jets from the carburetor body. Flip the unit right side up and remove the throttle body with a crescent wrench. Pull off any remaining gasket material from the unit.
- 5
  Spray the entire carburetor body with carburetor cleaner solvent, with special attention to nooks and crannies as well as cavities where the jets screw in. Allow the carburetor body to air-dry.
- 6
  Open the rebuild kit and spread out the new gaskets and jets. Begin rebuilding the carburetor, reversing Steps 3 to 5. Replace all the jets with those included in the rebuild kit. Do not reuse old gaskets.
- 7
  Reattach the air filter and throttle assembly. Lock them in place with a crescent wrench and screwdriver. Position the carburetor unit back onto the engine intake and bolt it into place on the intake manifold. Reattach the throttle cable and fuel line. Tighten the fuel-line clamp with a screwdriver.
- 8
  Power up the airplane engine and test the carburetor to ensure it is working properly.

Aviation