Revs not dropping to idle

Hi all.

1992 Clipper 1.8 carb engine with factory carb.

It has sat rather too long since last used. I took the battery off and charged it over the weekend and put it back on and tried the car today.  After a minutes cranking fuel came through and the engine burst into life, but at about 2,500 revs.
I let it warm up, the revs didn’t drop, so I turned it off and , checked the hoses to the carb and they were hot, then started it again and this times the revs fall off to about 1000, so I ran round to use the airline at the filling station and pump up the tires.

I thought I would test it around the Leicester ring road and after a few miles the revs won’t drop again. 3000 revs sitting at the traffic lights. It was like that for about five miles, and then suddenly becomes normal within half a mile of home.

Any ideas to get me started?  Please don’t comment if it’s going to be “get a Weber”.

Thanks all.

Accell cable that needs lubed, the internal cable sticking in the sheath,  Can POP the Cable off and use Tri-Flow spray in to the cable, then hang the cable via a string or rope up in the air so the lube has a chance to work.

Sticky linkages on the Carb not allowing the butterfly to return to normal, seen this on cars that have set a while and the Butterfly and Mech gets gummy.  Heat and use eventually unsticks it, cleaning and lubing the Mech and Carb can clean.

Vacuum leaks can also cause a variety of issues, just some of the things I have fought over the years.

Decades ago I had a return spring on one of my SU carbs on my MG Failed, causing a similar issue and I got a ticket for going 40 in a 35, in second gear as it wouldn't throttle down,  sad part was I was only a mile from the house after driving it that way for about 45 minutes.

Thanks for the suggestions.  The vacuum hoses do look dodgy so as they need doing anyway, I will try them first. I have seen others find that this fixed things for them.