How to Rebuild a Two Cycle Carburetor


Do It Yourself Outdoor Power Equipment Repair

2-Cycle Carburetor Rebuild Instructions


This handy guide will teach you how to rebuild a two cycle carburetor.

Step 1:
2-Cycle Carburetor Rebuilding Step 1Remove four screws (32) from purge pump side of carburetor.

 

 

 

 

 


Step 2:
Remove purge pump (33), metering chamber (12) and fuel pump gaskets / diaphragms (44).


Step 3:
2-Cycle Carburetor Rebuilding Step 3Inspect all gaskets and diaphragms for brittleness, wrinkles and tears.  Replace as required.

 

 

 


Step 4:
2-Cycle Carburetor Rebuilding Step 4Remove and replace the fuel inlet screen (5).
Use a rod of 2mm (0.1 in) diameter for removing and 7.6mm (0.3 inch)
diameter for installing.

 

 

 

 

 

 

 


Step 5:
2-Cycle Carburetor Rebuilding Step 5Remove main jet (18) from carburetor body with a small screw driver as illustrated.

Inspect jet orifice for blockages or damage.

Clean with compressed air or replace if necessary.

Replace O-ring (35) if damaged.

 


Step 6:
2-Cycle Carburetor Rebuilding Step 6Inspect the inlet valve assembly for damaged components or dirt on the Needle Seats.

Note: This valve must hold a minimum of 0.5 kg/cm2 (7 PSI) when in closed position.

 

 

 


Step 7:
2-Cycle Carburetor Rebuilding Step 7To remove the lever (9), axle (34) spring (8) and needle (7), simply pry the axle (34) from the metering chamber body.

Use care not to damage any components.

 

 

 

 


Step 8:
2-Cycle Carburetor Rebuilding Step 8Clean all components and adjust lever height to 1.5mm (0.06 inch) below gasket surface of the metering chamber body as shown.

 

 

 


Step 9:
Disconnect fuel return line from carburetor.


Step 10:
2-Cycle Carburetor Rebuilding Step 9 thru 12Connect pressure tester (31) to return fitting on carburetor.

 

 

 

 

 


Step 11:

2-Cycle Carburetor Rebuilding Step 9 thru 12Pump purge pump bulb (15) several times until the pressure tester shows 0.5 kg/cm2 (7 PSI).

 

 

 

 

 

 


Step 12:

If the tester does not hold CONTACT at this range, remove and inspect the purge pump.


Step 13:

2-Cycle Carburetor Rebuilding Step 13Clean the purge pump (33) with a minimum of 2 kg/cm2 (28 PSI) compressed air.

 

 

 

 

 


Step 14:
2-Cycle Carburetor Rebuilding Step 14Pay particular attention to clean the brass check valves but be careful not to damage them.

Recheck the pump operation after reassembly.  If problems persist, replace the pump body.

Note: Do not attempt to remove the check valves (21, 22) as they will be damaged.

 

 

 

 


Step 15:
2-Cycle Carburetor Rebuilding Step 15Reassemble the carburetor in reverse order of disassembly.

Pay special attention to cleanliness during reassembly.

 

 

 

 


Step 16:
2-Cycle Carburetor Rebuilding Step 16Check gaskets and diaphragms for correct installation by referring to the location in order of their corresponding tabs (30).

 

 

 


Step 17:
2-Cycle Carburetor Rebuilding Step 17After reassembly, pressure test the fuel pump and inlet valve to insure proper seal.  It must hold a minimum of 0.5 kg/cm2 (7 PSI).

 

 

 

2-Cycle Carburetor Rebuilding

2-Cycle Carburetor Rebuilding

– Jack Hayes

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Jack Hayes

Jack Hayes

Jack Hayes is the Head of Internet Marketing at LawnMowerPros and the editor of this blog. You can often find him creating featured articles, DIY guides, custom graphics and much more.