Idling to Save...

Idling to Save…

By Tim Ard, Forest Applications Training, Inc.

Since cooler weather has come upon most chainsaw operations this year, I find age old idling problems again to still be a major issue. Consistently, every class and operation observed, at least a couple saws are idling too high or will not stay running at idle.

When a saw idles at too high RPM it creates issues that are just not good...

1. If a clutch and saw chain doesn't disengage at idle, the operator is put into a position that could end in a loss of control and laceration. Idle should be set low enough to disengage the clutch and the saw chain should stop all rotation.


2. Excessive heat and wear is created on the centrifugal clutch and drum as the clutch shoes and springs slip inside the drum. Especially when the chain brake is applied.

When a saw will not idle…

1. When the throttle is released the engine dies and has to be restarted. Often distressing the operator and taking concentration off the work at hand.


2. The starter system and rope receive a lot more stress and wear than necessary.

There are several steps to adjusting a chainsaw carburetor and you should consult your owners manual or your local dealer before making any adjustments, but the first step to adjustment can be accomplished without a screwdriver.

Is my chainsaw adjusted correctly? Follow these simple checks…

Assuming - Fresh, properly mixed fuel in tank. Engine will start. Air Filter is clean.

1. Air filter clean, start and warm up to run temperature.


2. Run up to full throttle. The engine should approach top no load RPM and level out. RPM should not continue to climb. We call this level RPM engine sound a high speed flutter. If RPM continues to climb the H screw adjustment is too lean.


3. Reduce throttle. The chain should stop any rotation and creep. If rotation continues adjustment to the T or LA screw is necessary.


4. With the saw idling, apply chain brake and roll the saw over, up and down. It should continue to idle without significant RPM change or dyeing. If idle doesn't continue, the L setting is too rich.


5. Release chain brake and depress throttle quickly. The RPM should return to high flutter without any hesitation. If hesitation is existent, L screw adjustment is too lean.

These five will troubleshoot for you if adjustment is necessary. Remember, you don’t need to have a screwdriver to adjust your saw. If you know its out of adjustment, you can take it to someone who is trained to use one. If your saw does not pass the five - choosing not to adjust - can also have negative mechanical and safety outcomes.

Make sure your saw is Idling to Save and don’t forget to wear your PPE (Personal Protective Equipment) when checking or operating your chainsaw.

Good Sawing, Tim