Cleaning a small engine carburetor usually gets done as part of a carburetor rebuild, but there are a number of reasons why cleaning a carburetor without rebuilding it is also a good idea for tool owners.
Properly cleaning a 2-cycle engine carburetor means completely disassembling and reassembling the unit.
We explain the steps to disassemble and reassemble an example 2-cycle engine carburetor below, and we also explain the correct way to clean a carburetor while it's still disassembled.
Carburetor Disassembly Steps
This carburetor disassembly, cleaning, and rebuild demonstration is performed on a carburetor from a Ryobi 2-cycle grass trimmer. Steps for other carburetor cleanings will be similar to these.
Tip! Carburetors have many small parts. Keep carburetor parts organized in the order that they are removed (like in rows) to make reassembly fast and accurate.
Step 1: Remove the Bottom Plate
Unscrew the two screws that affix the lower cover plate to the carburetor body.The bottom plate is held on by four screws for some carburetor models.
Step 2: Remove the Diaphragm and Diaphragm Gasket--Separate Them if Needed.
The diaphragm gasket will often stick to the diaphragm when removing it from the carburetor body. If the diaphragm and diaphragm gasket are stuck together, they must be carefully separated from one another to be cleaned later.
Step 3: Remove the Needle Valve Mechanism
It will be visible in the body of the carburetor after the diaphragm is removed.
The needle valve mechanism is held into place by a retaining screw.
Unscrew the needle valve retaining screw to release the mechanism from the body of the carburetor.
Make sure to hold the spring-loaded mechanism in place as you remove the screw. This will stop the valve parts from flying across the workbench.