2-Cycle Carburetor Rebuild Instructions
This handy guide will teach you how to rebuild a two cycle carburetor.
Remove four screws (32) from purge pump side of carburetor.
Remove purge pump (33), metering chamber (12) and fuel pump gaskets / diaphragms (44).
Inspect all gaskets and diaphragms for brittleness, wrinkles and tears. Replace as required.
Remove 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.
Remove 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.
Inspect 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.
To 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.
Clean all components and adjust lever height to 1.5mm (0.06 inch) below gasket surface of the metering chamber body as shown.
Disconnect fuel return line from carburetor.
Connect pressure tester (31) to return fitting on carburetor.
Pump purge pump bulb (15) several times until the pressure tester shows 0.5 kg/cm2 (7 PSI).
If the tester does not hold CONTACT at this range, remove and inspect the purge pump.
Clean the purge pump (33) with a minimum of 2 kg/cm2 (28 PSI) compressed air.
Pay 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.
Reassemble the carburetor in reverse order of disassembly.
Pay special attention to cleanliness during reassembly.
Check gaskets and diaphragms for correct installation by referring to the location in order of their corresponding tabs (30).
After 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).
– Jack Hayes