How to Troubleshoot a Walbro Chainsaw Carburetor

Remove the Walbro carburetor from your chainsaw. This process will vary greatly from manufacturer to manufacturer, so read the manual for your product. Rotate the high- and low-speed jets clockwise until they are seated. Turn them counterclockwise one full revolution.

Fill the beaker with enough water to submerge the entire carburetor. Connect the carburetor pressure tester, inserting the tube into the inlet jet on the carburetor. Set the carburetor into the beaker of water, making sure it’s fully submerged.

Pump up the pressurizing bulb until the meter on the tester reads 50 kPA (.5 bar). Tighten the clamp on the pump’s tube. Watch the meter for several minutes to see if any leaking occurs.

Check for leaks if the pressure drops. Inspect the diffuser jets, the impulse tube and the metering unit’s ventilation hole. Replace any malfunctioning parts and diaphragms as necessary and repeat the pressure test.