Does anyone here have a cure for 'run-on' in a ' 70 B? Virtually every MGB I've ever encountered seems to run on after being switched off to some extent, particularly when warm. On well-used engines I wrote it off to a build-up of carbon in the combustion chambers, on valves, pistons etc. but my engine is freshly rebuilt, .040" oversize 9 to 1 pistons, half race cam, lightened flywheel, new carbs etc. etc. It runs and pulls very well, starts easily, gets good mileage, but when I shut off it gives a couple of coughs and a shudder before it dies.
I've tried playing with the timing and carburetion but nothing seems to make any difference.
Any help would be greatfully received.
Thanks in advance. KH Canada.