Engine cutting out when slowing down

[Everycloud]

Hi,
I've got a 1.9 water cooled, 1986 T25. Recently had new alternator, battery and starter motor, she's been sat for about a month or so and taken her out today hoping to use her this weekend but she's losing power when driving along and cuts out when I'm slowing down below 20 unless I keep the revs up. Starts on the button but just doest keep ticking over. Could it possibly a fuel supply issue? Ive been using super unleaded since the recently fuel change over (except one time when I didn't realise) I'd appreciate any help.
Thanks,
David

[maxstu]

Blocked jets. Do an Italian tune with a can of carb cleaner.
Remove plastic beret on top of carb. Get a mate to rev engine...l mean really rev the nuts off type of revving....and squirt small amounts of carb cleaner spray straight down the carb.

[jrt]

Check for a leak on vacuum pipes or as in my case the inlet manifold. Spray some carb’ cleaner/wd40 around the inlet manifold and pipes while it idles and see if the revs pick up.
David.