Join the jet set
QMy Ford Escort MKII is fitted with a Weber carburettor. It’s stopped idling and is spluttery at low revs, though it runs OK at higher speeds. I took the top off, but the float chamber seemed quite clean. Where can I look for the problem?
Dan Snell, Tamworth
AIt sounds as if the idling jet is blocked. It’s only tiny, so a little flake of debris is enough to stop the flow of fuel. You should find the jet on the side of the unit, about twothirds of the way up. You may see an external passageway running down towards the throttle butterfly, which confirms what the jet is for.
If it’s a twin-choke unit, the jet will be on the same side as the primary throttle barrel. If it’s closed by a screw plug, remove this and unscrew the jet behind it. It’s also possible that the jet is push-fitted in the end of a brass hexagon bolt or a solenoid valve.
Use compressed air and/or carburettor cleaner to clear the tiny hole that runs through the jet. If necessary, probe debris clear with the bristle of a paint brush – or a single strand of copper from a multistrand electrical wire if it’s really stubborn. Never use steel wire or excessive force as this will damage the very precise bore of the jet.