I have a zetec fitted with zx9carbs, however when the engine is running the carbs make a sqweeking noise in tune with the engine, is this normal? Or is it a leak or something?

sounds like an air leak, have the engine running and if you spray wd40 around the join/gasket it goes quiet and you can locate the leak hopefully.

sound like your sucking air in somewhere, try spraying wd40 or easy start around the rubbers, if your engine note changes you have a leak !

hth

Ray

you do tend to get a strange induction noise from the zetec It sometimes sounds like you can hear the valves Ive noticed it on my car with twin 40's on and one running Injection but with bike carbs as TB's

if you have an air leak it normally sounds like a birdy tweeting