pierburg 2e3 problem

[theoriginalGhostman]

Hi, just a quick one, what would cause idle to rise from 1000 rpm, (when first fired up) to around 1700 when up to temp? the revs just slowly climb as it warms up? i'm guessing an air leak of some kind, will this cause above problem? any way of telling where its leaking?

car is a standard 1200 with complete 2e3 carb/manifold fitted, its had a manual choke fitted at some point, but thats not hooked up atm. i never took the carb off the manifold between pullin it off at the scrappy an fitting it, should i have done and put a new carb gasket in?

thanks in advance
dan.