My engine is running to fast on my Petrol Chainsaw

Overview

If your petrol chainsaw is revving higher than normal or running at excessive speed, it is usually caused by a throttle control issue, incorrect choke position, or a cable that is sticking or misaligned. Carry out the checks below before continuing to use the machine.

Step-by-Step Guide

Step 1: Safety First

• Stop using the chainsaw immediately if the engine is over-revving
• Engage the chain brake
• Place the chainsaw on a stable surface
• Ensure the chain is not able to rotate freely during inspection

Step 2: Check the Throttle Cable

• Inspect the throttle cable for damage or wear
• Check for kinks, tight bends, or trapped sections
• Ensure the cable moves freely when the trigger is released

A sticking or damaged cable can prevent the throttle from returning to idle.

Step 3: Check the Choke Position

• Confirm the choke is fully disengaged after starting
• A partially engaged choke can cause abnormal engine speed and performance issues

Ensure the choke lever is fully in the “run” position during operation.

Step 4: Reset the Throttle Control

• Press and release the throttle trigger several times
• This resets the throttle return mechanism
• Confirm the trigger returns smoothly to its resting position

Step 5: Check the Trigger Cable Guide

• Inspect where the trigger cable exits the handle
• Ensure the cable guide is correctly seated in its housing
• A misaligned guide may prevent smooth throttle movement

Important Safety Information

• Never operate the chainsaw if it is over-revving
• Always engage the chain brake during inspection
• Do not force the throttle or trigger mechanism
• Stop use immediately if the engine does not return to idle

Frequently Asked Questions

Why is my chainsaw revving high even when I’m not touching the trigger?

This is usually caused by a sticking throttle cable or misaligned cable guide preventing the throttle from returning to idle.

Can the choke cause high engine speed?

Yes. If the choke is not fully disengaged, it can affect engine behaviour and cause abnormal running.

Is it safe to continue using the chainsaw?

No. If the engine is running too fast, stop using it until the cause is identified and corrected.

What if the throttle still doesn’t return properly?

The cable or trigger assembly may be damaged and should be inspected by technical support or a qualified repair centre.

Could fuel issues cause this?

Fuel issues more commonly cause rough running or stalling, not continuous high revving, which is usually throttle-related.