Thanks Tim, that’s very helpful. As ever you are a font of knowledge.
Regarding sooty plugs, which is a pretty good description of mine, I recently increased the size of my idle jets to 49, so that wouldn’t have helped, but is there way of making the tickover mixture leaner?
I’ll try to take the car out soon and see what the plugs look like after run at a reasonable speed. I understand the best way is to put it into neutral then turn the engine off and coast to a stop to avoid any chance of sooting up at low revs.
I’m starting to appreciate why fuel injection was invented!
You really want to eliminate the sooty plugs first!!! Before seeing if main jet is correct (it will be). Regardless of idle jet size the mix is set at idle through the 4 idle mix screws.... Everything has to be correct (valve timing, ignition timing, synchronization, tappets) and it is an iterative process between synch and mix.