I love blatting about in my 1976 Mini, but something I've never quite understood is why the hot idle speed/ quality changes in relation to how full the fuel tank is.
With a full tank, the hot idle is smooth and a little too fast for my liking.
When the tank gets to around 1/3 full, the idle progressively gets slower and becomes choppy to to the point I give it a little throttle to keep the drops gears from chattering.
There are no other running faults.
The spec is as follows-
Standard 1098cc with 12G202 head, Minispares st1 kit, standard HS4 carb with red jet and original small fuel tank.
Any ideas why the hot idle is so variable? Nothing else seems to affect it, just the level of fuel in the tank...