ECHO chain saws come equipped with a purge pump, also called a buffer bulb or primer button, that delivers a burst of gasoline and 2-cycle oil into the carburetor whenever the pump is pushed. The injection of oil and fuel to the carburetor makes it easier to begin a cold engine once you’ve pushed the purge pump the recommended 3 to 4 times. When the purge pump functions up or stops functioning, it’s time to replace it with a new one.
Purge Pump Part
As the years pass, the rubber of the purge pump might harden and lose its flexibility. It also can crack, allowing air to the lines and decreasing its ability to pull the fuel/oil mixture to the engine. Since the purge pump on an ECHO chain saw consists of the rubber pump wax, and the plastic foundation and straps that home the arc, problems also can arise if the plastic becomes dry and brittle, possibly splitting or breaking.
Problem Diagnosis
If you’re new to having a purge pump on a part of gas-powered equipment, you might question whether the problem actually is the purge pump. When you press the purge pump, then you should feel a small resistance to the pressure as the primer bulb pulls the fuel to the motor. If the pressure is not there, the purge pump probably is defective. Cracks from the rubber of the primer bulb and visible leakage in the buffer arc or across the purge pump assembly is just another positive sign that it’s time for replacement.
Safety Measures
Before replacing the purge pump over the ECHO chain saw, guarantee that the motor is totally cool, particularly if the chain saw was in use lately. Working on a warm or hot string saw poses the chance of burns that range from minor to severe. Remove the spark plug wire from the spark plug before attempting any repair job to guarantee the machine doesn’t engage accidentally. Situate the chain saw a flat, solid surface to make sure that it doesn’t shift position as you’re creating the fix.
Purge Pump Replacement
Access the purge pump assembly by removing both black clips that hold the orange top cover in place on the chain saw. Lift the cover and then lay it aside. Pop from the tabs that hold the purge pump assembly in position with a flat-head screwdriver and pull the assembly in the body of the chain saw. Attach both fuel lines that emerge in the chain saw into the two ports around the purge pump, ensuring that you reattach the tubes into the proper ports, one long one and one short one. Pop the assembly to the casing of the chain saw. Replace the cover and fasten the clips that hold it in position. Prime the string saw 3 to 4 times before trying to start it after the repair.