EXPLAINER: HOW TO SET YOUR IDLE MIXTURE

Warm up the engine thoroughly by driving the car a few miles not just by idling it, if possible.

Make sure the idle speed is normal - around 800-1000 rpm, or see your manual.

Turn the fuel mixture screw out to enrich the mixture until the engine starts to slow down. Now wind it back in, weakening the mix until the engine starts to run less smoothly and slow down again.

In between these extremes you should find the ‘sweet spot’ which gives the perfect idle mixture for the engine. It ticks over smoothly and evenly, the exhaust isn’t pungent and it doesn’t stall out if you raise the revs then release the throttle.

Reset the idle speed if needed.