Idle Speed

Specification
Updated 2026-08-24 · Read this page as Markdown

The engine speed, in revolutions per minute (rpm), at which the saw runs with the throttle released. It must be set low enough that the clutch stays disengaged and the chain does not move.

A chain that creeps at idle is a genuine hazard and always means the idle speed is set too high or the clutch is worn — it is one of the first things to check on a used saw. Idle speed is a carburettor adjustment (the T or LA screw) and drifts over time with altitude, fuel and engine wear, so it is a normal part of servicing rather than a fixed property of the machine. The figure also matters for restarting: too low and the engine stalls every time you set the saw down between cuts.

This spec across the catalog

Recorded on 16 models in this database, from 2700 rpm to 3000 rpm, averaging 2837.5 rpm.

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Related terms

Decompression valve A small button-operated valve that vents part of the cylinder pressure during starting, making the engine much easier to pull over. It closes automatically as soon as the engine fires. Easy-start system A starter mechanism that uses a spring between the recoil rope and the crankshaft to store the energy of a slow pull and release it in one burst, turning the engine over for you. Manufacturers market it under names such as SmartStart, EasyStart or Soft Start. Engine Displacement The swept volume of the chainsaw's cylinder, measured in cubic centimetres (cc). It is the single figure most often used to place a petrol saw in its size class, because displacement broadly tracks both power and weight. Maximum Speed The highest engine speed the saw is designed to reach, in revolutions per minute (rpm), usually quoted with the bar and chain fitted. It is the reference point for carburettor tuning and for the chain speed figure. Power Output The maximum power the engine or motor delivers, stated in kilowatts (kW). It determines how well the saw holds chain speed when the cutters are loaded in the cut, rather than how fast it spins free. Power Output (HP) The same maximum power figure expressed in horsepower (hp) instead of kilowatts. One kilowatt equals approximately 1.34 hp.

See also

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