The throttle cable is one of the most important parts of your chainsaw. In order for your chainsaw to run at all, it needs the throttle cable to be attached to both the throttle trigger and the carburetor. You see, when you pull the trigger, the throttle cable enables fuel to flow so that the chainsaw will run. Without the throttle cable, there is no way for the throttle trigger to activate the chain. It’s like firing a weapon without a hammer to connect to the primer.
Every chainsaw comes with a safety feature that ensures the chain only spins when the top trigger is pushed firmly down, and the bottom trigger is squeezed. Without your throttle cable properly installed, the chain on your chainsaw will never spin.
If you are having a bit of trouble installing your throttle cable, this informative guide on how to connect the throttle cable to the carburetor will help. You may need to do this to repair your chainsaw, and it can be confusing if you took the chainsaw apart and have forgotten how to reassemble it.
Here are the steps you take to install and connect the throttle cable.
Step 1: Close the Choke Lever
First, you must close the choke lever by moving it into the closed position. This will prevent dirt from getting inside the carburetor. Proceed by unscrewing the protective cover of the air filter and lifting the filter cover out. Then you will need to get the grommet off of the carburetor box. You can usually do this easily by just popping off the grommet.
Step 2: Remove the Air Filter
Now you must remove the entire air filter. You can usually do this by unscrewing the slotted nuts and then removing the entire air filter from the top of the carburetor. By now you will see the throttle cable running from the carburetor to the trigger. If you are installing a new trigger wire, you will need to unscrew the first one.
Step 3: Take Out Old Throttle Cable
Now you can unscrew the handle molding screw from the bottom of the back handle. Take away the handle mold and cover and you will see the naked trigger. You can now manually shift the master control lever into the “on” position, which is labeled generally with an “I” on the handle side.
Now lift the throttle interlock lever out of its seat, which is still inside the handle. You should be able to take out the old throttle cable from where it is connected to the trigger. Disconnect the old throttle cable and put it aside.
Basically, what you are doing here is taking apart the handle to get access to the trigger, and therefore to the throttle cable. It is impossible to remove or install the throttle cable without disassembling the handle.
And while this is a detailed set of instructions, it may not work with every model of every chainsaw. Many different models from many different manufacturers differ in how they are constructed. But what they all have in common is that a throttle cable will always connect to the carburetor from the main trigger.
Step 4: Install the New Throttle Cable
With the old throttle cable removed, you can now install the new throttle cable. You will need to push the new cable inside the seat on the trigger. It is basically like connecting wire into a circuit board. Once the throttle cable is attached to the trigger, you can once more push the throttle interlock lever into the down position.
Reverse the master control lever from the “on” position into the “stop” position, the exact opposite of what you did in the last step. Now, take all the pieces of the handle and reinstall it so that it looks just the way it did before. You should now be able to wind the throttle cable into its proper seat on the side of the carburetor.
You will want to attach the throttle cable in the exact same way it was before you removed the old one. It is important that you look closely at how the throttle wire is positioned inside of the machine, as you will want to copy it exactly. It may even be beneficial to take a photo once you have the guts of the chainsaw opened up.
Step 5: Seal Everything Up
Now its time to seal everything up. You will need to refit the grommet so that it is back in the same position. Push the grommet snuggly into place over the carburetor’s adjustment screws by just using your thumb. You can also place the air filter back where it belonged and tighten the nuts back in place, thus securing the filter to the carburetor.
Once the air filter’s cover has been placed over it, you are ready to go. Congratulations, you have just installed a new throttle cable on your chainsaw. If you have any problems once starting the tool, it is likely you made a mistake along the way. I recommend double-checking the connection at each end of the throttle cable.
How to Connect Throttle Cable to Carb: Final Thoughts
Now you know how to install a new throttle cable. To recap, the throttle cable is what connects the trigger with the carburetor. I want you to think about the throttle cable as the cord to a trap. When you squeeze the trigger, the cord is pulled taut and a vent is opened on the carburetor which allows gas to flow freely into the mixing chamber.
The harder you squeeze the trigger, the wider the vent is opened and the more power the engine receives. In fact, this works exactly the same as a car. The further you push the pedal down on the car, the more fuel is delivered into your combustion engine. This is basically how every combustion engine on the planet works.
Sometimes, the throttle cable can become detached from either side, either the trigger or the carburetor, if you have dropped your chainsaw, smashed it off a tree, or in some other way damaged it. However, throttle cables are inexpensive, and as you can see from this guide, very easy to install.