How To Replace The Primer Bulb On Chainsaws
When your chainsaw sits unused for a period of time, the fuel will drain and evaporate out of the carburetor. And when it comes to using the chainsaw next, the engine can not start until the carburetor once again has fuel in it. The purge bulb, more commonly called the primer bulb, manually pumps fuel into the carburetor, which purges the air out of the carb.
Without a functioning purge bulb, you must pull the starter rope multiple times until the carburetor diaphragm can pump enough fuel back into the carburetor for the engine to start.
Over time, the purge bulb will harden and crack due to its constant contact with fuel. Once cracked, it will no longer pump fuel into the carb, causing a hard starting engine. Replacing the primer bulb is a repair that you can do yourself.
Before you start, you need to drain the fuel out of your chainsaw.
Step 1: Remove the top cover and the starter assembly.
Step 2: Remove the air filter and the air filter base.
Step 3: Remove the carburetor. There are several pieces you need to remove to do that. You can start by removing the choke lever. Then you can remove the fuel line coming from the primer bulb to the carburetor. Pull the throttle trigger on the saw to give yourself access to the throttle linkage. Pull it away and remove it from the carburetor. Now you can pull the carb away from the saw.
Step 4: Remove the primer bulb. Commonly, there are two tabs on the bottom of the primer bulb. You can use a screwdriver to pry the old one out of the saw housing and remove the two fuel lines from it.
Within the chainsaw fuel system, the fuel should flow from the fuel filter into the carburetor, from the carb to the primer, and then from the primer, any excess fuel should flow back into the fuel tank. So you need to figure out which side of the carburetor is pulling fuel and which is going to return it back to the tank.
The easiest way is to place your finger over the openings on the back of the primer bulb. And then begin to prime. The side that is pulling fuel when blocked will make the primer bulb become soft, it may even stay compressed as you pull or as you prime it. On the other side, when you block it off will keep the primer bulb stiff because air can not get out of it.
Now you can go ahead and assemble the primer bulb back into the saw.
Step 5: Reinstall all the fuel lines and put other pieces back into position.
HIPA PRIMER BULB
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